fix: sanitize plugin manifest name in plugin-manager add to prevent p…#671
Open
RanWurmbrand wants to merge 1 commit into
Open
fix: sanitize plugin manifest name in plugin-manager add to prevent p…#671RanWurmbrand wants to merge 1 commit into
RanWurmbrand wants to merge 1 commit into
Conversation
…ath traversal and plugin override Signed-off-by: Ran Wurmbrand <rwurmbra@redhat.com>
📝 WalkthroughWalkthroughPlugin binary installation now validates manifest filenames for path traversal and existing targets before performing retrieval or filesystem writes. ChangesPlugin installation validation
Estimated code review effort: 2 (Simple) | ~10 minutes Suggested reviewers: 🚥 Pre-merge checks | ✅ 5✅ Passed checks (5 passed)
✨ Finishing Touches🧪 Generate unit tests (beta)
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 |
Test Coverage ReportTotal: 49.1% Per-package coverage
Full function-level detailsPosted by CI |
![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
🤖 Prompt for all review comments with AI agents
Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.
Inline comments:
In `@cmd/plugin-manager/add/add.go`:
- Around line 217-221: Update the file creation logic in downloadBinary to
include os.O_EXCL alongside the existing creation flags, so opening the target
fails atomically if a file or symlink appears during download; also use
executable mode 0755 instead of 0777.
- Around line 205-215: The validateFileInput function must use os.Lstat to
inspect the destination without following symlinks, and treat any error other
than os.ErrNotExist as a validation failure. Preserve the existing
duplicate-file error for an existing path, while rejecting broken symlinks and
propagating unexpected filesystem errors before installation.
🪄 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: 407cee60-227b-49d0-9410-e2eae0785a98
📒 Files selected for processing (1)
cmd/plugin-manager/add/add.go
Comment on lines
+205
to
+215
| func validateFileInput(filepath, filename string) error { | ||
| if strings.Contains(filename, "/") || strings.Contains(filename, "\\") || strings.Contains(filename, "..") { | ||
| return fmt.Errorf("invalid plugin name %q: must not contain path separators or traversal sequences", filename) | ||
| } | ||
|
|
||
| existingPath := filepath + "/" + filename | ||
| if _, err := os.Stat(existingPath); err == nil { | ||
| return fmt.Errorf("a plugin named %q already exists at %s, please remove it first before installing", filename, existingPath) | ||
| } | ||
| return nil | ||
| } |
There was a problem hiding this comment.
🔒 Security & Privacy | 🟠 Major | ⚡ Quick win
🧩 Analysis chain
🏁 Script executed:
#!/bin/bash
# Description: Check current imports in add.go to determine if path/filepath and errors need to be added.
rg '^import ' -A 15 cmd/plugin-manager/add/add.goRepository: migtools/crane
Length of output: 411
🏁 Script executed:
sed -n '180,280p' cmd/plugin-manager/add/add.go
python3 - <<'PY'
import os, tempfile, pathlib, stat
with tempfile.TemporaryDirectory() as d:
p = pathlib.Path(d) / "broken"
try:
p.symlink_to(pathlib.Path(d) / "missing")
except (OSError, NotImplementedError) as e:
print("symlink_unavailable", type(e).__name__, e)
else:
try:
os.stat(p)
except OSError as e:
print("stat", type(e).__name__, e.errno)
try:
os.lstat(p)
except OSError as e:
print("lstat", type(e).__name__, e.errno)
PYRepository: migtools/crane
Length of output: 3309
🏁 Script executed:
python3 - <<'PY'
import os, tempfile, pathlib
with tempfile.TemporaryDirectory() as d:
base = pathlib.Path(d)
target = base / "outside.txt"
link = base / "plugin"
link.symlink_to(target) # broken symlink
print("before_exists", target.exists())
try:
with open(link, "w") as f:
f.write("hello")
print("open_succeeded", True)
except OSError as e:
print("open_succeeded", False, type(e).__name__, e.errno)
print("after_exists", target.exists())
if target.exists():
print("target_contents", target.read_text())
PYRepository: migtools/crane
Length of output: 232
Use os.Lstat and fail closed on unexpected errors in cmd/plugin-manager/add/add.go:205-215. os.Stat follows symlinks, so a broken symlink at the destination can slip past this guard and the later os.OpenFile(..., O_CREAT|O_TRUNC, 0777) will write through it. Treat any non-os.ErrNotExist error as a failure here.
🤖 Prompt for AI Agents
Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.
In `@cmd/plugin-manager/add/add.go` around lines 205 - 215, The validateFileInput
function must use os.Lstat to inspect the destination without following
symlinks, and treat any error other than os.ErrNotExist as a validation failure.
Preserve the existing duplicate-file error for an existing path, while rejecting
broken symlinks and propagating unexpected filesystem errors before
installation.
Source: Coding guidelines
Comment on lines
217
to
+221
| func downloadBinary(filepath string, filename string, url string, log *logrus.Logger) error { | ||
| if err := validateFileInput(filepath, filename); err != nil { | ||
| return err | ||
| } | ||
|
|
There was a problem hiding this comment.
🔒 Security & Privacy | 🟠 Major | ⚡ Quick win
Use os.O_EXCL during file creation to prevent TOCTOU race conditions.
While validateFileInput provides a fast early check, a Time-of-Check to Time-of-Use (TOCTOU) race condition exists because the binary is downloaded over the network before the local file is actually created. If a file or symlink is created at the target path concurrently during the download, opening the file with syscall.O_TRUNC will overwrite it or follow the symlink to overwrite an arbitrary file.
To strictly enforce the protection against overwrites, use os.O_EXCL in os.OpenFile when creating the plugin binary (around line 249) to guarantee the operation fails atomically if the file already exists.
🔒 Proposed fix for file creation
Update the file creation logic (around line 249) to use os.O_EXCL and apply a safer default mode for executables (0755 instead of world-writable 0777):
- pluginBinary, err := os.OpenFile(filepath+"/"+filename, syscall.O_RDWR|syscall.O_CREAT|syscall.O_TRUNC, 0777)
+ pluginBinary, err := os.OpenFile(filepath+"/"+filename, os.O_RDWR|os.O_CREAT|os.O_EXCL, 0755) // Update to use filepath.Join if parameter was renamed🤖 Prompt for AI Agents
Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.
In `@cmd/plugin-manager/add/add.go` around lines 217 - 221, Update the file
creation logic in downloadBinary to include os.O_EXCL alongside the existing
creation flags, so opening the target fails atomically if a file or symlink
appears during download; also use executable mode 0755 instead of 0777.
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
1 participant
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
closes: #670
Summary
The
plugin-manager addcommand uses thenamefield from the plugin manifest as the binary filename without any sanitization. This allows a malicious plugin repository to:nameto an already-installed plugin (e.g.OpenShiftPlugin), silently replacing it with a trojanized versionnamecontaining../../sequences escapes the plugins directory, writing an executable (0777 permissions) to arbitrary pathsRoot Cause
In
downloadBinary(),value.Namefrom the manifest YAML is passed directly toos.OpenFileas the filename with no validation.Fix
Added a
validateFileInput()function that runs before any download:/,\, or..— blocks path traversalPoC
Full end-to-end proof of concept: https://github.com/RanWurmbrand/compromised-plugins
Test plan
crane plugin-manager add EvilPluginwith a manifest name containing../../is rejected with an errorcrane plugin-manager add CoolPluginwith a manifest name matching an existing plugin (OpenShiftPlugin) is rejected with an errorSummary by CodeRabbit