🛡️ Sentinel: [HIGH] Fix insecure temporary file usage#51
🛡️ Sentinel: [HIGH] Fix insecure temporary file usage#51
Conversation
- Replace predictable `/tmp/yq` path with securely generated directory using `mktemp -d`. - Apply same secure temporary directory pattern to Go and lsd downloads. - Log security learning in `.jules/sentinel.md`. Co-authored-by: kidchenko <5432753+kidchenko@users.noreply.github.com>
|
👋 Jules, reporting for duty! I'm here to lend a hand with this pull request. When you start a review, I'll add a 👀 emoji to each comment to let you know I've read it. I'll focus on feedback directed at me and will do my best to stay out of conversations between you and other bots or reviewers to keep the noise down. I'll push a commit with your requested changes shortly after. Please note there might be a delay between these steps, but rest assured I'm on the job! For more direct control, you can switch me to Reactive Mode. When this mode is on, I will only act on comments where you specifically mention me with New to Jules? Learn more at jules.google/docs. For security, I will only act on instructions from the user who triggered this task. |
📝 WalkthroughWalkthroughDocumentation was added describing a historical security vulnerability in OS installer scripts involving insecure temporary file handling. The Changes
Estimated code review effort🎯 3 (Moderate) | ⏱️ ~20 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 unit tests (beta)
Tip Try Coding Plans. Let us write the prompt for your AI agent so you can ship faster (with fewer bugs). Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out. Comment |
![coderabbitai[bot]](https://avatars.githubusercontent.com/in/347564?s=60&v=4){kind=small}
There was a problem hiding this comment.
Actionable comments posted: 2
🧹 Nitpick comments (1)
tools/os_installers/apt.sh (1)
208-212: Make temp-dir cleanup run on failure too.With
set -e, any error betweenmktemp -dand the trailingrm -rfexits the script early and leaves the temp directory behind. Wrapping each download/install step in a subshell with anEXITtrap would preserve the cleanup guarantee on both success and failure.Example pattern for the Go block
if ! command -v go &> /dev/null; then GO_VERSION="1.23.4" - TMP_DIR=$(mktemp -d) - wget "https://go.dev/dl/go${GO_VERSION}.linux-amd64.tar.gz" -O "$TMP_DIR/go${GO_VERSION}.linux-amd64.tar.gz" - sudo rm -rf /usr/local/go - sudo tar -C /usr/local -xzf "$TMP_DIR/go${GO_VERSION}.linux-amd64.tar.gz" - rm -rf "$TMP_DIR" + ( + TMP_DIR=$(mktemp -d) + trap 'rm -rf "$TMP_DIR"' EXIT + wget "https://go.dev/dl/go${GO_VERSION}.linux-amd64.tar.gz" -O "$TMP_DIR/go${GO_VERSION}.linux-amd64.tar.gz" + sudo rm -rf /usr/local/go + sudo tar -C /usr/local -xzf "$TMP_DIR/go${GO_VERSION}.linux-amd64.tar.gz" + ) echo "NOTE: Add 'export PATH=\$PATH:/usr/local/go/bin' to your shell profile" fiApply the same pattern to the
yqandlsdblocks.Also applies to: 235-239, 246-249
🤖 Prompt for AI Agents
Verify each finding against the current code and only fix it if needed. In `@tools/os_installers/apt.sh` around lines 208 - 212, The temp-dir created by TMP_DIR=$(mktemp -d) is not guaranteed to be removed if any command fails; wrap the Go download/install sequence (the TMP_DIR creation, wget, tar extraction, and final rm -rf) in a short-lived block/subshell that sets a trap on EXIT to remove "$TMP_DIR" (and clears the trap on success) so cleanup runs on both success and failure; apply the same pattern to the yq and lsd blocks (their mktemp/TMP_DIR, wget/curl and unpack/remove sequences) and reference the same symbols (TMP_DIR, mktemp, wget/curl, tar, rm -rf, and the EXIT trap) when implementing the fix.
🤖 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: Update the dated entry header "2025-03-07 - [Fix Insecure
Temporary File Usage in OS Installers]" to the correct PR date (2026-03-07),
promote that heading to H1 (prepend a single "# "), ensure there is a blank line
above and below the heading, and reflow the prose paragraphs in that block so
lines are wrapped to the repo's preferred width (fixing MD013) and satisfy
MD022/MD041 heading-level and blank-line rules.
In `@tools/os_installers/apt.sh`:
- Around line 208-212: The script currently downloads and unpacks remote release
artifacts (see TMP_DIR, GO_VERSION, wget and sudo tar usage) without verifying
integrity; change each install block (Go, yq, lsd and any dpkg installs) to
fetch the official checksum or signature file from the vendor, verify the
downloaded archive using sha256sum (or gpg/openssl signature verification for
signed releases), fail and exit if the verification fails, and only then proceed
to extract or install (tar, dpkg, mv); ensure verification uses the
vendor-provided URL and that TMP_DIR cleanup still runs on both success and
failure.
---
Nitpick comments:
In `@tools/os_installers/apt.sh`:
- Around line 208-212: The temp-dir created by TMP_DIR=$(mktemp -d) is not
guaranteed to be removed if any command fails; wrap the Go download/install
sequence (the TMP_DIR creation, wget, tar extraction, and final rm -rf) in a
short-lived block/subshell that sets a trap on EXIT to remove "$TMP_DIR" (and
clears the trap on success) so cleanup runs on both success and failure; apply
the same pattern to the yq and lsd blocks (their mktemp/TMP_DIR, wget/curl and
unpack/remove sequences) and reference the same symbols (TMP_DIR, mktemp,
wget/curl, tar, rm -rf, and the EXIT trap) when implementing the fix.
ℹ️ Review info
⚙️ Run configuration
Configuration used: defaults
Review profile: CHILL
Plan: Pro
Run ID: e4ef4ebd-d8ab-4038-9393-0399d78ac8f3
📒 Files selected for processing (2)
.jules/sentinel.mdtools/os_installers/apt.sh
| ## 2025-03-07 - [Fix Insecure Temporary File Usage in OS Installers] | ||
| **Vulnerability:** Predictable temporary file locations (`/tmp/yq`) and current working directory downloads during package installation in `tools/os_installers/apt.sh`. | ||
| **Learning:** Using predictable paths like `/tmp/filename` allows local privilege escalation and symlink attacks. Downloading directly to the current working directory is untidy and may leave artifacts behind or conflict with existing files. | ||
| **Prevention:** Always use securely generated temporary directories like `mktemp -d` to handle downloads and intermediate files during scripts. |
There was a problem hiding this comment.
Correct the date and heading format so docs lint passes.
This entry is dated 2025-03-07, but the PR was opened on March 7, 2026. The same block also hits MD041/MD022/MD013, so the docs lint job will stay red until the heading is promoted to H1, blank lines are added, and the prose is wrapped.
Proposed fix
-## 2025-03-07 - [Fix Insecure Temporary File Usage in OS Installers]
-**Vulnerability:** Predictable temporary file locations (`/tmp/yq`) and current working directory downloads during package installation in `tools/os_installers/apt.sh`.
-**Learning:** Using predictable paths like `/tmp/filename` allows local privilege escalation and symlink attacks. Downloading directly to the current working directory is untidy and may leave artifacts behind or conflict with existing files.
-**Prevention:** Always use securely generated temporary directories like `mktemp -d` to handle downloads and intermediate files during scripts.
+# 2026-03-07 - Fix insecure temporary file usage in OS installers
+
+**Vulnerability:** Predictable temporary file locations (`/tmp/yq`) and
+current-working-directory downloads during package installation in
+`tools/os_installers/apt.sh`.
+
+**Learning:** Using predictable paths like `/tmp/filename` allows local
+privilege escalation and symlink attacks. Downloading directly to the current
+working directory is untidy and may leave artifacts behind or conflict with
+existing files.
+
+**Prevention:** Always use securely generated temporary directories like
+`mktemp -d` to handle downloads and intermediate files during scripts.📝 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.
| ## 2025-03-07 - [Fix Insecure Temporary File Usage in OS Installers] | |
| **Vulnerability:** Predictable temporary file locations (`/tmp/yq`) and current working directory downloads during package installation in `tools/os_installers/apt.sh`. | |
| **Learning:** Using predictable paths like `/tmp/filename` allows local privilege escalation and symlink attacks. Downloading directly to the current working directory is untidy and may leave artifacts behind or conflict with existing files. | |
| **Prevention:** Always use securely generated temporary directories like `mktemp -d` to handle downloads and intermediate files during scripts. | |
| # 2026-03-07 - Fix insecure temporary file usage in OS installers | |
| **Vulnerability:** Predictable temporary file locations (`/tmp/yq`) and | |
| current-working-directory downloads during package installation in | |
| `tools/os_installers/apt.sh`. | |
| **Learning:** Using predictable paths like `/tmp/filename` allows local | |
| privilege escalation and symlink attacks. Downloading directly to the current | |
| working directory is untidy and may leave artifacts behind or conflict with | |
| existing files. | |
| **Prevention:** Always use securely generated temporary directories like | |
| `mktemp -d` to handle downloads and intermediate files during scripts. |
🧰 Tools
🪛 GitHub Check: Lint Documentation
[failure] 4-4: Line length
.jules/sentinel.md:4:81 MD013/line-length Line length [Expected: 80; Actual: 143] 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: 241] 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: 168] 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: "## 2025-03-07 - [Fix Insecure ..."] 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: "## 2025-03-07 - [Fix Insecure Temporary File Usage in OS Installers]"] 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, Update the dated entry header
"2025-03-07 - [Fix Insecure Temporary File Usage in OS Installers]" to the
correct PR date (2026-03-07), promote that heading to H1 (prepend a single "#
"), ensure there is a blank line above and below the heading, and reflow the
prose paragraphs in that block so lines are wrapped to the repo's preferred
width (fixing MD013) and satisfy MD022/MD041 heading-level and blank-line rules.
| TMP_DIR=$(mktemp -d) | ||
| wget "https://go.dev/dl/go${GO_VERSION}.linux-amd64.tar.gz" -O "$TMP_DIR/go${GO_VERSION}.linux-amd64.tar.gz" | ||
| sudo rm -rf /usr/local/go | ||
| sudo tar -C /usr/local -xzf "go${GO_VERSION}.linux-amd64.tar.gz" | ||
| rm "go${GO_VERSION}.linux-amd64.tar.gz" | ||
| sudo tar -C /usr/local -xzf "$TMP_DIR/go${GO_VERSION}.linux-amd64.tar.gz" | ||
| rm -rf "$TMP_DIR" |
There was a problem hiding this comment.
Verify release artifacts before installing them.
These blocks still unpack or install vendor binaries directly from the network. If an upstream release asset is tampered with, this script will promote attacker-controlled content into privileged locations. Please verify the official checksum or signature for Go, yq, and lsd before tar, mv, or dpkg.
Also applies to: 235-239, 246-249
🤖 Prompt for AI Agents
Verify each finding against the current code and only fix it if needed.
In `@tools/os_installers/apt.sh` around lines 208 - 212, The script currently
downloads and unpacks remote release artifacts (see TMP_DIR, GO_VERSION, wget
and sudo tar usage) without verifying integrity; change each install block (Go,
yq, lsd and any dpkg installs) to fetch the official checksum or signature file
from the vendor, verify the downloaded archive using sha256sum (or gpg/openssl
signature verification for signed releases), fail and exit if the verification
fails, and only then proceed to extract or install (tar, dpkg, mv); ensure
verification uses the vendor-provided URL and that TMP_DIR cleanup still runs on
both success and failure.
1 participant
🚨 Severity: HIGH
💡 Vulnerability: The
tools/os_installers/apt.shscript downloadsyqto a predictable temporary file path (/tmp/yq) and then moves it usingsudo. This exposes the system to symlink attacks and local privilege escalation. Other downloads (Go, lsd) pull files into the current working directory, which is untidy and potentially problematic.🎯 Impact: A local attacker could pre-create a symlink at
/tmp/yqpointing to a critical system file, causing the subsequentsudo mvcommand to overwrite the target.🔧 Fix: Used
mktemp -dto create a securely generated temporary directory for downloadingyq, Go, and lsd, ensuring downloads are isolated and safe before being processed.✅ Verification: Ran
./build.shto ensure script syntax is valid, manually inspectedtools/os_installers/apt.shlogic, and successfully received a correct rating on automated code review.PR created automatically by Jules for task 9613855591027540940 started by @kidchenko
Summary by CodeRabbit
Bug Fixes