Peekaboo Linux Gnome Wayland Computer Use

• Outcome: Review
• Latest audit: Sep 16, 2026 · 9:13 AM UTC
• Version: 1.0.2

Overview

This skill openly enables powerful remote viewing and control of a GNOME desktop, but it also installs persistent control components and gives unsafe remote-access setup guidance that users should review carefully.

Install only on a machine and user account where remote screen capture and input control are explicitly authorized. Pin and review the GNOME extensions before enabling them, avoid reusing or printing RDP/Linux passwords, keep SSH/RDP LAN- or VPN-scoped, and disable lingering, ydotoold, RDP, and the extensions when the automation is no longer needed.

A.I.G

Vulnerability Patterns

• Remote Payload Retrieval and Execution: Fetches external code whose behavior can change after review
• Unauthorized Access and Privilege Escalation: Obtains permissions beyond the task's legitimate needs
• Insecure Skill Coding Practices: Finds exploitable flaws such as hardcoded secrets or command injection
• Skill Instruction Hijacking: Alters the agent's session goals or safety constraints when the skill loads
• Agent Memory Poisoning: Writes attacker-controlled rules into memory that affect later sessions

Findings (4)

T03 · Remote Payload Retrieval and Execution

Error

• Location: references/peekaboo-and-rdp-setup-ubuntu-gnome-wayland.md:49

Finding

Unpinned Remote GNOME Shell Extensions Are Retrieved and Executed

Content

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Remediation

View remediation

' test "$(git -C /tmp/project rev-parse HEAD)" = '' ``` 2. Prefer signed release tags and verify the signature against a documented maintainer key. 3. Publish and verify SHA-256 hashes for every installed extension file. 4. Vendor reviewed extension sources into the Skill package where licensing permits. 5. Do not copy or enable an extension until its JavaScript and metadata have been reviewed. 6. Document the exact audited extension versions rather than references such as `master`. 7. Limit enabled extensions to the dedicated automation account and provide explicit disable/uninstall commands. ]]>

T09 · Insecure Skill Coding Practices

Error

• Location: references/peekaboo-and-rdp-setup-ubuntu-gnome-wayland.md:169

Finding

RDP Credential Instructions Expose Passwords and Encourage Credential Reuse

Content

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``` The guide later recommends reusing the Linux login password and displaying stored credentials: ```bash To make it feel like one login, **set the device credential equal to the target user's Linux password** so the same `user`/`password` works at both prompts: ```bash # password via STDIN — never as an arg (args leak to ps/process list and shell history) printf '%s\n' "$THE_USER_PW" | sudo grdctl --system rdp set-credentials sudo systemctl restart gnome-remote-desktop.service sudo grdctl --system status --show-credentials | grep -iE 'username|password' # verify the unix login password matches (so the GDM stage takes the same pw): printf '%s\n' "$THE_USER_PW" | su -c 'echo OK' ``` ``` ### Technical Analysis The argument-based `set-credentials` example contradicts the adjacent warning not to inline passwords. Once a real password replaces the placeholder, it may be recorded in shell history and can potentially be exposed through process inspection, terminal capture, audit logging, or agent transcripts. The `--show-credentials` command deliberately emits credential material to standard output. Piping it through `grep` does not protect the value and may place it in terminal logs, CI output, support bundles, or agent context. The recommendation to make the RDP device password identical to the Linux account password expands the consequences of either credential being disclosed. Compromise of a network-facing RDP credential would then also disclose the local account credential used at GDM, through PAM, and potentially for `sudo`. No hidd ...[truncated 1425 chars]

Remediation

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' unset RDP_PASSWORD ``` 4. Never invoke `status --show-credentials` in routine verification. Verify only that credentials are configured, without displaying the secret. 5. Use a unique, randomly generated RDP device credential rather than the Linux login password. 6. Redact credentials from terminal transcripts, agent logs, shell history, and support bundles. 7. Restrict RDP at the firewall to explicitly trusted source addresses and rotate any credential that may already have been exposed. ]]>

T09 · Insecure Skill Coding Practices

Warning

• Location: scripts/screenshot-display.py:98

Finding

Race-Prone Temporary File Used for Sensitive Desktop Screenshots

Content

View full analysis

Remediation

View remediation

T05 · Unauthorized Access and Privilege Escalation

Warning

• Location: references/rdp-auth-diagnosis-server-side.md:109

Finding

RDP Troubleshooting Recommends Broad Privileged Termination of VPN Processes

Content

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Remediation

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.service' ``` 4. Require explicit user confirmation before changing VPN or endpoint-security state. 5. Warn that restarting the VPN may expose or interrupt traffic, and pause sensitive network activity first. 6. Document how to verify that the VPN, kill switch, routes, and DNS protections have recovered. 7. Avoid performing this action when the VPN is the only trusted management channel. ]]>

SkillSpector

Vulnerability Patterns

• Data Exfiltration: External Transmission, Env Variable Harvesting, File System Enumeration
• Privilege Escalation: Excessive Permissions, Sudo/Root Execution, Credential Access
• Excessive Agency: Unrestricted Tool Access, Autonomous Decision Making, Scope Creep
• Tool Misuse: Tool Parameter Abuse, Chaining Abuse, Unsafe Defaults
• Rogue Agent: Self-Modification, Session Persistence

Findings (78)

Ae1

High

• Category: analysis-evasion
• Confidence: 100% confidence

Finding

Referenced artifact was not completely inspected

Content

Scanner excerpt · SKILL.md (reported line 132)May include surrounding context.

md

`references/peekaboo-and-rdp-setup-ubuntu-gnome-wayland.md`.

Ae1

High

• Category: analysis-evasion
• Confidence: 100% confidence

Finding

Referenced artifact was not completely inspected

Content

Scanner excerpt · SKILL.md (reported line 247)May include surrounding context.

md

`references/peekaboo-and-rdp-setup-ubuntu-gnome-wayland.md`.

Ssd 3

High

• Category: Not specified by scanner
• Confidence: 97% confidence

Finding

The document provides a turnkey workflow for persistent screenshot capture, window enumeration, and synthetic input on GNOME Wayland desktops. In context, this is a powerful surveillance-and-control capability: an agent can continuously inspect private on-screen data and interact with applications as the logged-in user, which is highly sensitive if deployed outside tightly controlled environments.

Content

No source excerpt is available for this finding.

Ssd 3

High

• Category: Not specified by scanner
• Confidence: 95% confidence

Finding

The guide explicitly aims to preserve agent-related user services across logout/reboot via lingering and autologin assumptions, enabling continuous desktop access over time. Persistence amplifies the harm of any compromise by allowing long-lived collection of screenshots, UI state, and possibly typed secrets without requiring repeated operator action.

Content

No source excerpt is available for this finding.

Chaining Abuse

High

• Category: Tool Misuse
• Confidence: 75% confidence

Finding

Tool calls are chained to bypass individual safety checks or escalate capabilities beyond what any single tool call would allow.

Content

Scanner excerpt · references/peekaboo-and-rdp-setup-ubuntu-gnome-wayland.md (reported line 81)May include surrounding context.

md

sudo apt-get install -y ydotool
# /dev/uinput must be writable by the user. If it's not already ACL'd, add a udev rule:
#   echo 'KERNEL=="uinput", GROUP="input", MODE="0660", OPTIONS+="static_node=uinput"' \
#     | sudo tee /etc/udev/rules.d/99-uinput.rules
#   sudo usermod -aG input "$USER"   # then re-login
mkdir -p ~/.config/systemd/user
cat > ~/.config/systemd/user/ydotoold.service <<'EOF'

Ssd 3

High

• Category: Not specified by scanner
• Confidence: 96% confidence

Finding

The RDP section gives a direct path to exposing the login screen and user session to remote operators, including service enablement, certificate setup, credentials, and firewall opening. That substantially increases attack surface and can reveal credentials, sensitive desktop content, and session access to anyone who obtains the RDP credentials or reaches the service.

Content

No source excerpt is available for this finding.

Chaining Abuse

High

• Category: Tool Misuse
• Confidence: 75% confidence

Finding

Tool calls are chained to bypass individual safety checks or escalate capabilities beyond what any single tool call would allow.

Content

Scanner excerpt · references/peekaboo-and-rdp-setup-ubuntu-gnome-wayland.md (reported line 164)May include surrounding context.

md

sudo openssl req -newkey rsa:2048 -nodes -keyout "$SYS/rdp-tls.key" \
     -x509 -days 3650 -out "$SYS/rdp-tls.crt" -subj "/CN=$(hostname)"
sudo chown gnome-remote-desktop:gnome-remote-desktop "$SYS/rdp-tls".{key,crt}
sudo chmod 600 "$SYS/rdp-tls.key"; sudo chmod 644 "$SYS/rdp-tls.crt"
# 2) enable the SYSTEM service + set TLS
sudo systemctl enable --now gnome-remote-desktop.service
sudo grdctl --system rdp set-tls-key  "$SYS/rdp-tls.key"

Chaining Abuse

High

• Category: Tool Misuse
• Confidence: 90% confidence

Finding

Piping a plaintext password into sudo grdctl is not command-injection abuse, but in context it operationalizes direct handling of reusable credentials for a remote access service. Combined with the surrounding recommendation to align the RDP credential with the Unix account password, it increases exposure of high-value secrets and normalizes insecure credential workflows.

Content

Scanner excerpt · references/peekaboo-and-rdp-setup-ubuntu-gnome-wayland.md (reported line 192)May include surrounding context.

password** so the same user/password works at both prompts:

bash

# password via STDIN — never as an arg (args leak to ps/process list and shell history)
printf '%s\n' "$THE_USER_PW" | sudo grdctl --system rdp set-credentials <user>
sudo systemctl restart gnome-remote-desktop.service       # apply it to the live daemon
sudo grdctl --system status --show-credentials | grep -iE 'username|password'   # readback to confirm
# verify the unix login password matches (so the GDM stage takes the same pw):

Chaining Abuse

High

• Category: Tool Misuse
• Confidence: 89% confidence

Finding

Piping the user's password to su for verification is an unsafe credential-handling pattern that normalizes scripting with plaintext account passwords. Even if intended for confirmation, it increases the chance of secret exposure through shell environment leakage, operator error, terminal logging, or copy/paste into insecure contexts.

Content

Scanner excerpt · references/peekaboo-and-rdp-setup-ubuntu-gnome-wayland.md (reported line 196)May include surrounding context.

sudo systemctl restart gnome-remote-desktop.service # apply it to the live daemon sudo grdctl --system status --show-credentials | grep -iE 'username|password' # readback to confirm

verify the unix login password matches (so the GDM stage takes the same pw):

printf '%s\n' "$THE_USER_PW" | su -c 'echo OK' # prints OK if the pw is correct

text

If the user's Linux password later rotates, re-run the `set-credentials` line **and restart the
service** to keep the two stages in sync.

Env Variable Harvesting

High

• Category: Data Exfiltration
• Confidence: 60% confidence

Finding

Code enumerates, copies, or searches environment variables for secrets. Bulk environment access can collect credentials unrelated to the skill's stated purpose.

Content

Scanner excerpt · scripts/locate-element.py (reported line 36)May include surrounding context.

python

WINDOWS_IFACE = "org.gnome.Shell.Extensions.Windows"

def _env():
    e = dict(os.environ)
    e.setdefault("XDG_RUNTIME_DIR", "/run/user/%d" % os.getuid())
    e.setdefault("DBUS_SESSION_BUS_ADDRESS", "unix:path=%s/bus" % e["XDG_RUNTIME_DIR"])
    return e

Env Variable Harvesting

High

• Category: Data Exfiltration
• Confidence: 60% confidence

Finding

Code enumerates, copies, or searches environment variables for secrets. Bulk environment access can collect credentials unrelated to the skill's stated purpose.

Content

Scanner excerpt · scripts/screenshot-display.py (reported line 29)May include surrounding context.

python

WINDOWS_IFACE = "org.gnome.Shell.Extensions.Windows"

def _env():
    e = dict(os.environ)
    e.setdefault("XDG_RUNTIME_DIR", "/run/user/%d" % os.getuid())
    e.setdefault("DBUS_SESSION_BUS_ADDRESS", "unix:path=%s/bus" % e["XDG_RUNTIME_DIR"])
    return e

Undeclared Tool Scope

Medium

• Category: MCP Least Privilege
• Confidence: 98% confidence

Finding

The skill exposes powerful shell and environment-dependent capabilities but does not declare any tool scope or permission boundary. In practice it enables screenshot capture, desktop input injection, remote SSH control, service management, and extension installation, so the absence of explicit allowed-tools/permissions creates a dangerous mismatch between stated contract and real authority.

Content

No source excerpt is available for this finding.

Session Persistence

Medium

• Category: Rogue Agent
• Confidence: 91% confidence

Finding

The skill recommends running agents under systemd --user with lingering enabled so they survive SSH disconnects, which establishes persistence for a process that can observe and control the desktop. Persistence materially raises the security risk because a compromised or misconfigured agent can continue interacting with the session after the initiating operator disconnects.

Content

Scanner excerpt · SKILL.md (reported line 46)May include surrounding context.

md

non-login shells — `XDG_RUNTIME_DIR=/run/user/UID`,
  `DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/UID/bus`, `WAYLAND_DISPLAY=wayland-0`, `DISPLAY=:0`.
  (Replace `UID` with the session user's numeric id, e.g. `1000`.)
- If agents run under `systemd --user` with the full graphical session env + lingering enabled,
  they inherit all of the above and survive SSH disconnects.
- `gnome-screenshot` grabs the **full virtual desktop** (all monitors stitched). On multi-4K
  setups that's huge — use `-w` (focused window) or the per-display helper below.

Missing User Warnings

Medium

• Category: Not specified by scanner
• Confidence: 92% confidence

Finding

The skill instructs remote screenshot capture and transfer over SSH/SCP without prominently warning that full desktop images may contain passwords, tokens, personal data, internal documents, or customer information. Because the capture is of the active graphical session and may include all monitors, the privacy and data-exfiltration risk is substantial even if SSH itself is encrypted.

Content

No source excerpt is available for this finding.

Sudo/Root Execution

Medium

• Category: Privilege Escalation
• Confidence: 86% confidence

Finding

This step invokes sudo apt-get install, which requires elevated privileges and expands the host's software footprint. While common for setup, embedding privileged package installation in an automation skill increases the risk of unintended system modification and broadens the consequences if the skill is misused or run on the wrong host.

Content

Scanner excerpt · SKILL.md (reported line 83)May include surrounding context.

Installing the extension from scratch

bash

# [NATIVE or over SSH with the session env exported]
sudo apt-get install -y gnome-screenshot
D=~/.local/share/gnome-shell/extensions/[e-mail]
git clone --depth 1 https://github.com/siddhpant/allow-gnome-screenshot.git /tmp/ags
mkdir -p "$D" && cp -r /tmp/ags/[e-mail]/* "$D/"

Sudo/Root Execution

Medium

• Category: Privilege Escalation
• Confidence: 97% confidence

Finding

Restarting gdm3 with sudo is a privileged action that tears down the active graphical session, potentially interrupting users, killing in-flight work, and changing session state. In a remote automation context this is especially risky because it can act like a denial-of-service against the desktop and may disrupt monitoring or recovery access.

Content

Scanner excerpt · SKILL.md (reported line 87)May include surrounding context.

md

D=~/.local/share/gnome-shell/extensions/[e-mail]
git clone --depth 1 https://github.com/siddhpant/allow-gnome-screenshot.git /tmp/ags
mkdir -p "$D" && cp -r /tmp/ags/[e-mail]/* "$D/"
sudo systemctl restart gdm3      # reload the Shell so it discovers the extension (see WARNING below)
# after the session returns:
export XDG_RUNTIME_DIR=/run/user/UID DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/UID/bus
gnome-extensions enable [e-mail]

Missing User Warnings

Medium

• Category: Not specified by scanner
• Confidence: 95% confidence

Finding

The skill documents remote input injection into the active desktop session over SSH but lacks a clear warning that this can directly trigger destructive actions, send messages, approve prompts, modify data, or interfere with a live user's session. Since it targets the real GUI of a logged-in user, misuse can cause immediate integrity and availability impacts.

Content

No source excerpt is available for this finding.

Session Persistence

Medium

• Category: Rogue Agent
• Confidence: 88% confidence

Finding

Enabling ydotoold.service as a user service creates persistent input-injection capability within the session. Although useful for functionality, persistent background control infrastructure increases the blast radius of accidental use or post-compromise abuse because GUI input injection remains readily available.

Content

Scanner excerpt · SKILL.md (reported line 154)May include surrounding context.

export XDG_RUNTIME_DIR=/run/user/UID YDOTOOL_SOCKET=/run/user/UID/.ydotool_socket ydotool mousemove -a 700 400; ydotool click 0xC0; ydotool type "hi"'

text

If `ydotoold.service` is down — `systemctl --user enable --now ydotoold.service`. For element
targeting (not blind coords) use the `locate-element` helper below.

## CAPABILITY B+ — Click an element by role/name (SOM via hybrid coords)

Sudo/Root Execution

Medium

• Category: Privilege Escalation
• Confidence: 84% confidence

Finding

The documented restart of gnome-remote-desktop.service is a privileged action that changes remote access availability and authentication behavior. Although presented as troubleshooting, privileged manipulation of a remote desktop service is sensitive because mistakes can expose, disable, or destabilize remote access paths.

Content

Scanner excerpt · SKILL.md (reported line 231)May include surrounding context.

md

**⚠️ #1 RDP gotcha — credential changes need a daemon restart.** `grdctl --system rdp set-credentials`
writes the keyfile but the **running daemon does NOT hot-reload it into its NTLM SAM**. Until you
`sudo systemctl restart gnome-remote-desktop.service`, NLA fails for every client:
`ntlm_fetch_ntlm_v2_hash: Could not find user in SAM database` → `SEC_E_NO_CREDENTIALS` →
`transport_accept_nla: client authentication failure`. Meanwhile `grdctl status` shows the correct
creds (it reads the file). Clients report this as **`FREERDP_ERROR_CONNECT_TRANSPORT_FAILED`** (RoyalTS)

Sudo/Root Execution

Medium

• Category: Privilege Escalation
• Confidence: 95% confidence

Finding

The skill explicitly recommends restarting gdm3 to reload screenshot-related capabilities, which is a privileged and disruptive action affecting the active GUI session. Because the skill's purpose is unattended computer control, normalizing this step increases the chance that an agent or operator uses a high-impact administrative action as part of routine automation.

Content

Scanner excerpt · SKILL.md (reported line 267)May include surrounding context.

md

## Pitfalls

- The screenshot unlock is **binary-scoped** — only the `gnome-screenshot` binary is allowlisted. A raw gdbus Screenshot call still fails. Always shell out to `gnome-screenshot`.
- **Reloading the Shell on Wayland = restarting GDM** (`sudo systemctl restart gdm3`). There's no in-place `Alt+F2 r` over SSH. The **live GUI session is briefly torn down**, so don't do it mid-GUI-task. If autologin is enabled the desktop recovers in ~12s; `systemd --user` services survive if lingering is on. Verify recovery: `loginctl list-sessions` shows a `seat0` `Type=wayland Active=yes` session.
- **Never use the gdb `unsafe_mode` injection** — it crashes gnome-shell. Use the extension.
- **The `allow-gnome-screenshot` extension can silently flip to INACTIVE** (its allowlist hook only re-arms on a fresh Shell init). Symptom: `gnome-screenshot -f` exits 0 but writes no file. A disable/enable cycle is NOT enough — it needs a Shell reload (`sudo systemctl restart gdm3`) to re-arm. If you depend on capture in an automated loop, verify the file exists each time and reload-on-miss. (Window Calls can flip too — re-enable after any GDM restart.)
- `gnome-screenshot -a` (interactive area) needs a human at the screen — useless headless; use `-f` (full) or `-w` (window).

Session Persistence

Medium

• Category: Rogue Agent
• Confidence: 80% confidence

Finding

Skill establishes unauthorized persistence across sessions via cron jobs, startup scripts, or state files. Session persistence allows an attacker to maintain access beyond the current interaction.

Content

Scanner excerpt · SKILL.md (reported line 267)May include surrounding context.

md

## Pitfalls

- The screenshot unlock is **binary-scoped** — only the `gnome-screenshot` binary is allowlisted. A raw gdbus Screenshot call still fails. Always shell out to `gnome-screenshot`.
- **Reloading the Shell on Wayland = restarting GDM** (`sudo systemctl restart gdm3`). There's no in-place `Alt+F2 r` over SSH. The **live GUI session is briefly torn down**, so don't do it mid-GUI-task. If autologin is enabled the desktop recovers in ~12s; `systemd --user` services survive if lingering is on. Verify recovery: `loginctl list-sessions` shows a `seat0` `Type=wayland Active=yes` session.
- **Never use the gdb `unsafe_mode` injection** — it crashes gnome-shell. Use the extension.
- **The `allow-gnome-screenshot` extension can silently flip to INACTIVE** (its allowlist hook only re-arms on a fresh Shell init). Symptom: `gnome-screenshot -f` exits 0 but writes no file. A disable/enable cycle is NOT enough — it needs a Shell reload (`sudo systemctl restart gdm3`) to re-arm. If you depend on capture in an automated loop, verify the file exists each time and reload-on-miss. (Window Calls can flip too — re-enable after any GDM restart.)
- `gnome-screenshot -a` (interactive area) needs a human at the screen — useless headless; use `-f` (full) or `-w` (window).

Sudo/Root Execution

Medium

• Category: Privilege Escalation
• Confidence: 95% confidence

Finding

This section reiterates that a shell reload requires sudo systemctl restart gdm3, again normalizing a privileged session-disrupting action inside an automation-focused skill. Repetition in operational guidance increases likelihood of misuse and elevates denial-of-service risk to the active desktop session.

Content

Scanner excerpt · SKILL.md (reported line 269)May include surrounding context.

md

- The screenshot unlock is **binary-scoped** — only the `gnome-screenshot` binary is allowlisted. A raw gdbus Screenshot call still fails. Always shell out to `gnome-screenshot`.
- **Reloading the Shell on Wayland = restarting GDM** (`sudo systemctl restart gdm3`). There's no in-place `Alt+F2 r` over SSH. The **live GUI session is briefly torn down**, so don't do it mid-GUI-task. If autologin is enabled the desktop recovers in ~12s; `systemd --user` services survive if lingering is on. Verify recovery: `loginctl list-sessions` shows a `seat0` `Type=wayland Active=yes` session.
- **Never use the gdb `unsafe_mode` injection** — it crashes gnome-shell. Use the extension.
- **The `allow-gnome-screenshot` extension can silently flip to INACTIVE** (its allowlist hook only re-arms on a fresh Shell init). Symptom: `gnome-screenshot -f` exits 0 but writes no file. A disable/enable cycle is NOT enough — it needs a Shell reload (`sudo systemctl restart gdm3`) to re-arm. If you depend on capture in an automated loop, verify the file exists each time and reload-on-miss. (Window Calls can flip too — re-enable after any GDM restart.)
- `gnome-screenshot -a` (interactive area) needs a human at the screen — useless headless; use `-f` (full) or `-w` (window).
- Full-desktop shots are huge (multi-4K). Prefer `-w`, or downscale before analysis.
- ydotool needs `ydotoold` alive + `YDOTOOL_SOCKET`/`XDG_RUNTIME_DIR`. Re-enable if it dies. Raw `ydotool` is blind absolute pixels — prefer `locate-element` (Capability B+) for element targeting.

Session Persistence

Medium

• Category: Rogue Agent
• Confidence: 80% confidence

Finding

Skill establishes unauthorized persistence across sessions via cron jobs, startup scripts, or state files. Session persistence allows an attacker to maintain access beyond the current interaction.

Content

Scanner excerpt · SKILL.md (reported line 269)May include surrounding context.

md

- The screenshot unlock is **binary-scoped** — only the `gnome-screenshot` binary is allowlisted. A raw gdbus Screenshot call still fails. Always shell out to `gnome-screenshot`.
- **Reloading the Shell on Wayland = restarting GDM** (`sudo systemctl restart gdm3`). There's no in-place `Alt+F2 r` over SSH. The **live GUI session is briefly torn down**, so don't do it mid-GUI-task. If autologin is enabled the desktop recovers in ~12s; `systemd --user` services survive if lingering is on. Verify recovery: `loginctl list-sessions` shows a `seat0` `Type=wayland Active=yes` session.
- **Never use the gdb `unsafe_mode` injection** — it crashes gnome-shell. Use the extension.
- **The `allow-gnome-screenshot` extension can silently flip to INACTIVE** (its allowlist hook only re-arms on a fresh Shell init). Symptom: `gnome-screenshot -f` exits 0 but writes no file. A disable/enable cycle is NOT enough — it needs a Shell reload (`sudo systemctl restart gdm3`) to re-arm. If you depend on capture in an automated loop, verify the file exists each time and reload-on-miss. (Window Calls can flip too — re-enable after any GDM restart.)
- `gnome-screenshot -a` (interactive area) needs a human at the screen — useless headless; use `-f` (full) or `-w` (window).
- Full-desktop shots are huge (multi-4K). Prefer `-w`, or downscale before analysis.
- ydotool needs `ydotoold` alive + `YDOTOOL_SOCKET`/`XDG_RUNTIME_DIR`. Re-enable if it dies. Raw `ydotool` is blind absolute pixels — prefer `locate-element` (Capability B+) for element targeting.

Missing User Warnings

Medium

• Category: Not specified by scanner
• Confidence: 89% confidence

Finding

The opening frames the procedure as enabling agent screenshots and input on a live desktop without an immediate privacy and consent warning. Because the capability directly permits observing on-screen content and injecting actions into a user session, lack of front-loaded disclosure increases the risk of misuse or accidental deployment in environments with sensitive data.

Content

No source excerpt is available for this finding.

Session Persistence

Medium

• Category: Rogue Agent
• Confidence: 71% confidence

Finding

Copying a GNOME Shell extension into the user's extensions directory creates a persistent capability change that survives shell restarts and reboots once enabled. In this case the extension re-allows screenshot capture that GNOME intentionally restricts, so persistence makes the bypass enduring rather than ephemeral.

Content

Scanner excerpt · references/peekaboo-and-rdp-setup-ubuntu-gnome-wayland.md (reported line 50)May include surrounding context.

Scoped to that one D-Bus sender; does NOT enable global unsafe_mode.

D=~/.local/share/gnome-shell/extensions/[e-mail] git clone --depth 1 https://github.com/siddhpant/allow-gnome-screenshot.git /tmp/ags mkdir -p "$D" && cp -r /tmp/ags/[e-mail]/* "$D/"

text

## Step 2 — Window enumeration / targeting (Window Calls extension)

Static analysis

No suspicious patterns detected.