🛡️ Sentinel: [CRITICAL] Fix predictable temporary file path vulnerability#79
🛡️ Sentinel: [CRITICAL] Fix predictable temporary file path vulnerability#79
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…lity - Replaced hardcoded `/tmp/yq` path in `tools/os_installers/apt.sh` with a secure random temporary directory using `mktemp -d`. - Wrapped temporary directory logic in a subshell and utilized an `EXIT` trap for automatic, safe cleanup without interfering with the parent script environment. - Documented learning in `.jules/sentinel.md` regarding TOCTOU and symlink attacks. Co-authored-by: kidchenko <5432753+kidchenko@users.noreply.github.com>
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📝 WalkthroughWalkthroughA security vulnerability in the Changes
Estimated code review effort🎯 2 (Simple) | ⏱️ ~10 minutes Poem
🚥 Pre-merge checks | ✅ 3✅ Passed checks (3 passed)
✏️ Tip: You can configure your own custom pre-merge checks in the settings. ✨ Finishing Touches📝 Generate docstrings
🧪 Generate unit tests (beta)
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Actionable comments posted: 1
🤖 Prompt for all review comments with AI agents
Verify each finding against the current code and only fix it if needed.
Inline comments:
In @.jules/sentinel.md:
- Around line 1-4: Change the markdown to start with a single top-level heading
and a blank line: replace the first line "## 2025-04-04 - Predictable Temporary
File Path Vulnerability in Package Download" with "# 2025-04-04 - Predictable
Temporary File Path Vulnerability in Package Download" and insert an empty line
after it; then wrap or break the long sentences in the body (the lines
describing Vulnerability, Learning, and Prevention) to 80 characters or fewer
per line so each paragraph adheres to the line-length limit.
🪄 Autofix (Beta)
Fix all unresolved CodeRabbit comments on this PR:
- Push a commit to this branch (recommended)
- Create a new PR with the fixes
ℹ️ Review info
⚙️ Run configuration
Configuration used: defaults
Review profile: CHILL
Plan: Pro
Run ID: 23e99ded-5bc2-4563-aad9-5d93ede88fac
📒 Files selected for processing (2)
.jules/sentinel.mdtools/os_installers/apt.sh
| ## 2025-04-04 - Predictable Temporary File Path Vulnerability in Package Download | ||
| **Vulnerability:** A package install script (`tools/os_installers/apt.sh`) downloaded the `yq` binary to a hardcoded, predictable temporary file path (`/tmp/yq`) before moving it to its final destination with elevated privileges (`sudo mv`). | ||
| **Learning:** Hardcoded temporary paths in shared directories (like `/tmp`) are vulnerable to Time-of-Check to Time-of-Use (TOCTOU) and symlink attacks, potentially allowing an attacker to overwrite arbitrary files or escalate privileges. | ||
| **Prevention:** Always use securely generated random directories (e.g., `mktemp -d`) for temporary files. Wrap the temporary operations in a subshell `(...)` and use `trap 'rm -rf "$TMP_DIR"' EXIT` to ensure the directory is automatically and safely cleaned up, without overriding global script traps. |
There was a problem hiding this comment.
Fix markdown linting failures.
The static analysis pipeline is failing due to markdown formatting issues:
- Line 1: Should start with a top-level heading (
#) and have a blank line after it - Lines 2-4: Exceed 80 character line length limit
📝 Proposed fix for markdown formatting
-## 2025-04-04 - Predictable Temporary File Path Vulnerability in Package Download
-**Vulnerability:** A package install script (`tools/os_installers/apt.sh`) downloaded the `yq` binary to a hardcoded, predictable temporary file path (`/tmp/yq`) before moving it to its final destination with elevated privileges (`sudo mv`).
-**Learning:** Hardcoded temporary paths in shared directories (like `/tmp`) are vulnerable to Time-of-Check to Time-of-Use (TOCTOU) and symlink attacks, potentially allowing an attacker to overwrite arbitrary files or escalate privileges.
-**Prevention:** Always use securely generated random directories (e.g., `mktemp -d`) for temporary files. Wrap the temporary operations in a subshell `(...)` and use `trap 'rm -rf "$TMP_DIR"' EXIT` to ensure the directory is automatically and safely cleaned up, without overriding global script traps.
+# Sentinel Security Learnings
+
+## 2025-04-04 - Predictable Temporary File Path Vulnerability in Package Download
+
+**Vulnerability:** A package install script (`tools/os_installers/apt.sh`)
+downloaded the `yq` binary to a hardcoded, predictable temporary file path
+(`/tmp/yq`) before moving it to its final destination with elevated privileges
+(`sudo mv`).
+
+**Learning:** Hardcoded temporary paths in shared directories (like `/tmp`) are
+vulnerable to Time-of-Check to Time-of-Use (TOCTOU) and symlink attacks,
+potentially allowing an attacker to overwrite arbitrary files or escalate
+privileges.
+
+**Prevention:** Always use securely generated random directories (e.g.,
+`mktemp -d`) for temporary files. Wrap the temporary operations in a subshell
+`(...)` and use `trap 'rm -rf "$TMP_DIR"' EXIT` to ensure the directory is
+automatically and safely cleaned up, without overriding global script traps.📝 Committable suggestion
‼️ IMPORTANT
Carefully review the code before committing. Ensure that it accurately replaces the highlighted code, contains no missing lines, and has no issues with indentation. Thoroughly test & benchmark the code to ensure it meets the requirements.
| ## 2025-04-04 - Predictable Temporary File Path Vulnerability in Package Download | |
| **Vulnerability:** A package install script (`tools/os_installers/apt.sh`) downloaded the `yq` binary to a hardcoded, predictable temporary file path (`/tmp/yq`) before moving it to its final destination with elevated privileges (`sudo mv`). | |
| **Learning:** Hardcoded temporary paths in shared directories (like `/tmp`) are vulnerable to Time-of-Check to Time-of-Use (TOCTOU) and symlink attacks, potentially allowing an attacker to overwrite arbitrary files or escalate privileges. | |
| **Prevention:** Always use securely generated random directories (e.g., `mktemp -d`) for temporary files. Wrap the temporary operations in a subshell `(...)` and use `trap 'rm -rf "$TMP_DIR"' EXIT` to ensure the directory is automatically and safely cleaned up, without overriding global script traps. | |
| # Sentinel Security Learnings | |
| ## 2025-04-04 - Predictable Temporary File Path Vulnerability in Package Download | |
| **Vulnerability:** A package install script (`tools/os_installers/apt.sh`) | |
| downloaded the `yq` binary to a hardcoded, predictable temporary file path | |
| (`/tmp/yq`) before moving it to its final destination with elevated privileges | |
| (`sudo mv`). | |
| **Learning:** Hardcoded temporary paths in shared directories (like `/tmp`) are | |
| vulnerable to Time-of-Check to Time-of-Use (TOCTOU) and symlink attacks, | |
| potentially allowing an attacker to overwrite arbitrary files or escalate | |
| privileges. | |
| **Prevention:** Always use securely generated random directories (e.g., | |
| `mktemp -d`) for temporary files. Wrap the temporary operations in a subshell | |
| `(...)` and use `trap 'rm -rf "$TMP_DIR"' EXIT` to ensure the directory is | |
| automatically and safely cleaned up, without overriding global script traps. |
🧰 Tools
🪛 GitHub Check: Lint Documentation
[failure] 4-4: Line length
.jules/sentinel.md:4:81 MD013/line-length Line length [Expected: 80; Actual: 301] https://github.com/DavidAnson/markdownlint/blob/v0.34.0/doc/md013.md
[failure] 3-3: Line length
.jules/sentinel.md:3:81 MD013/line-length Line length [Expected: 80; Actual: 238] https://github.com/DavidAnson/markdownlint/blob/v0.34.0/doc/md013.md
[failure] 2-2: Line length
.jules/sentinel.md:2:81 MD013/line-length Line length [Expected: 80; Actual: 241] https://github.com/DavidAnson/markdownlint/blob/v0.34.0/doc/md013.md
[failure] 1-1: First line in a file should be a top-level heading
.jules/sentinel.md:1 MD041/first-line-heading/first-line-h1 First line in a file should be a top-level heading [Context: "## 2025-04-04 - Predictable Te..."] https://github.com/DavidAnson/markdownlint/blob/v0.34.0/doc/md041.md
[failure] 1-1: Headings should be surrounded by blank lines
.jules/sentinel.md:1 MD022/blanks-around-headings Headings should be surrounded by blank lines [Expected: 1; Actual: 0; Below] [Context: "## 2025-04-04 - Predictable Temporary File Path Vulnerability in Package Download"] https://github.com/DavidAnson/markdownlint/blob/v0.34.0/doc/md022.md
🤖 Prompt for AI Agents
Verify each finding against the current code and only fix it if needed.
In @.jules/sentinel.md around lines 1 - 4, Change the markdown to start with a
single top-level heading and a blank line: replace the first line "## 2025-04-04
- Predictable Temporary File Path Vulnerability in Package Download" with "#
2025-04-04 - Predictable Temporary File Path Vulnerability in Package Download"
and insert an empty line after it; then wrap or break the long sentences in the
body (the lines describing Vulnerability, Learning, and Prevention) to 80
characters or fewer per line so each paragraph adheres to the line-length limit.
1 participant
🚨 Severity: CRITICAL
💡 Vulnerability: A package installation script (
tools/os_installers/apt.sh) previously downloaded theyqbinary to a hardcoded, predictable temporary file path (/tmp/yq) before callingsudo mv. This setup exposes the system to Time-of-Check to Time-of-Use (TOCTOU) and symlink attacks, potentially leading to arbitrary file overwriting or local privilege escalation.🎯 Impact: An attacker with local access could predict the path, overwrite
yqbefore it is moved, and inject a malicious binary into/usr/local/bin, thereby executing arbitrary code with elevated privileges.🔧 Fix: Modified the script to utilize
mktemp -dwithin a subshell ((...)), ensuring the directory is created securely. Addedtrap 'rm -rf "$TMP_DIR"' EXITfor safe and localized cleanup without disrupting global traps.✅ Verification:
tools/os_installers/apt.shno longer references/tmp/yq.yqinstallation usesmktemp -dwithin a subshell with proper traps../build.sh)..jules/sentinel.mdhas been updated with the corresponding security lesson.PR created automatically by Jules for task 10709256194709934029 started by @kidchenko
Summary by CodeRabbit
Bug Fixes
Documentation