🛡️ Sentinel: [MEDIUM] Fix insecure backup permissions

[kidchenko]

🛡️ Sentinel: [MEDIUM] Fix insecure backup permissions

🚨 Severity: MEDIUM
💡 Vulnerability: Project backups were created with default system permissions (often world-readable), potentially exposing sensitive source code.
🎯 Impact: Unauthorized local users could read the contents of backup archives.
🔧 Fix: Enforced umask 077 at the start of tools/backup-projects.sh.
✅ Verification: Verified with a reproduction script that new backups have -rw------- permissions.

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PR created automatically by Jules for task 230951383663742677 started by @kidchenko

Summary by CodeRabbit

• Bug Fixes

  • Backup files are now created with more restrictive permissions, ensuring they are readable and writable only by the owner, preventing unintended access to sensitive data.

• Documentation

  • Added security notes documenting backup permission requirements.

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[coderabbitai]

📝 Walkthrough

Walkthrough

The pull request addresses a permissions vulnerability in the backup script by documenting the security issue and implementing a fix. A new sentinel note describes how backup scripts can inadvertently create world-readable artifacts, while the backup script adds a umask 077 directive to enforce restrictive file permissions on generated backups.

Changes

Cohort / File(s)	Summary
Security Documentation .jules/sentinel.md	New sentinel note documenting a backup script permissions vulnerability, describing how default umask settings can result in world-readable sensitive artifacts and prescribing umask 077 as a preventive measure.
Backup Script Permission Fix tools/backup-projects.sh	Added global umask 077 setting at script startup to enforce strict permissions (rwx------) for all newly created files and directories during backup operations.

Estimated code review effort

🎯 1 (Trivial) | ⏱️ ~3 minutes

Poem

🐰 A lock for each backup, so snug and so tight,
With umask 077, permissions done right,
No peeking by neighbors, just owner may see,
Our sentinel notes guard security! 🔐

🚥 Pre-merge checks | ✅ 3

✅ Passed checks (3 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title uses an emoji and severity label format, but clearly communicates the main change: fixing insecure backup script permissions. It accurately reflects the primary objective of the PR.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

✨ Finishing Touches

• 📝 Generate docstrings (stacked PR)
• 📝 Generate docstrings (commit on current branch)

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment
• Commit unit tests in branch sentinel/fix-backup-permissions-230951383663742677

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[coderabbitai]

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: The markdown fails linting: change the opening "## 2026-02-21
- Insecure Backup Permissions" to a top-level heading by replacing it with "#
2026-02-21 - Insecure Backup Permissions" (this addresses MD041), add a blank
line immediately after that heading (MD022), and wrap or reflow the long lines
in the body (the lines referencing "Vulnerability:
`tools/backup-projects.sh`..." and "Prevention: Enforce `umask 077`..." and the
Learning line) so no line exceeds 80 characters (MD013); keep the same content
but split into shorter sentences or bullet lines to meet the limit.

[coderabbitai]

⚠️ Potential issue | 🟡 Minor

Fix markdown linting violations causing CI failures (MD041, MD022, MD013).

Five failures in the Lint Documentation check prevent a clean CI run:

• MD041: First line must be a top-level # heading — the file opens with ##.
• MD022: The ## heading requires a blank line below it.
• MD013: Lines 2–4 exceed the 80-character limit (actual: 145, 150, 104 chars).

📝 Proposed fix

-## 2026-02-21 - Insecure Backup Permissions
-**Vulnerability:** `tools/backup-projects.sh` created project backups with default umask permissions (often 644/755), making them world-readable.
-**Learning:** Scripts generating sensitive artifacts (backups, keys, logs) must explicitly set permissions. Default umask is insufficient for privacy.
-**Prevention:** Enforce `umask 077` at the start of any script that handles sensitive data or artifacts.
+# Sentinel Notes
+
+## 2026-02-21 - Insecure Backup Permissions
+
+**Vulnerability:** `tools/backup-projects.sh` created project backups with
+default umask permissions (often 644/755), making them world-readable.
+
+**Learning:** Scripts generating sensitive artifacts (backups, keys, logs) must
+explicitly set permissions. Default umask is insufficient for privacy.
+
+**Prevention:** Enforce `umask 077` at the start of any script that handles
+sensitive data or artifacts.

📝 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.

Suggested change

	## 2026-02-21 - Insecure Backup Permissions
	**Vulnerability:** `tools/backup-projects.sh` created project backups with default umask permissions (often 644/755), making them world-readable.
	**Learning:** Scripts generating sensitive artifacts (backups, keys, logs) must explicitly set permissions. Default umask is insufficient for privacy.
	**Prevention:** Enforce `umask 077` at the start of any script that handles sensitive data or artifacts.
	# Sentinel Notes
	## 2026-02-21 - Insecure Backup Permissions
	**Vulnerability:** `tools/backup-projects.sh` created project backups with
	default umask permissions (often 644/755), making them world-readable.
	**Learning:** Scripts generating sensitive artifacts (backups, keys, logs) must
	explicitly set permissions. Default umask is insufficient for privacy.
	**Prevention:** Enforce `umask 077` at the start of any script that handles
	sensitive data or artifacts.

🧰 Tools

🪛 GitHub Check: Lint Documentation

[failure] 4-4: Line length
.jules/sentinel.md:4:81 MD013/line-length Line length [Expected: 80; Actual: 104] https://github.com/DavidAnson/markdownlint/blob/v0.34.0/doc/md013.md

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[failure] 3-3: Line length
.jules/sentinel.md:3:81 MD013/line-length Line length [Expected: 80; Actual: 150] https://github.com/DavidAnson/markdownlint/blob/v0.34.0/doc/md013.md

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[failure] 2-2: Line length
.jules/sentinel.md:2:81 MD013/line-length Line length [Expected: 80; Actual: 145] 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: "## 2026-02-21 - Insecure Backu..."] 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: "## 2026-02-21 - Insecure Backup Permissions"] 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, The markdown fails linting: change
the opening "## 2026-02-21 - Insecure Backup Permissions" to a top-level heading
by replacing it with "# 2026-02-21 - Insecure Backup Permissions" (this
addresses MD041), add a blank line immediately after that heading (MD022), and
wrap or reflow the long lines in the body (the lines referencing "Vulnerability:
`tools/backup-projects.sh`..." and "Prevention: Enforce `umask 077`..." and the
Learning line) so no line exceeds 80 characters (MD013); keep the same content
but split into shorter sentences or bullet lines to meet the limit.