CVE-2021-28955 is a critical-severity (CVSS 9.8) CWE-427 vulnerability in github.com/MichaelMure/git-bug. A fix is available for github.com/MichaelMure/git-bug — see the affected versions and patch details below.
Arbitrary code execution due to an uncontrolled search path for the git binary
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2021-28955 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 385,738 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
github.com/MichaelMure/git-bugReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
Impact
The go language recently addressed a security issue in the way that binaries are found before being executed. Some operating systems like Windows persist to have the current directory being part of the default search path, and having priority over the system-wide path.
This means that it's possible for a malicious user to craft for example a git.bat command, commit it and push it in a repository. Later when git-bug search for the git binary, this malicious executable can take priority and be executed.
Who is impacted
This issue happen on Windows and some other operating systems with a badly configured PATH.
All version prior to 0.7.2 are vulnerable to this issue.
Patches
Version 0.7.2 fix this issue. Users should update as soon as possible.
References
More details about this issue can be found here.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/MichaelMure/git-bug | all versions | 0.7.2go get github.com/MichaelMure/git-bug@v0.7.2 |
Affected Products
git-buggit-bug_projectDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/MichaelMure/git-bug, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/MichaelMure/git-bug to 0.7.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-28955 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
Frequently Asked Questions
Is CVE-2021-28955 in your dependencies?
Find it across Go, including transitive dependencies.