CVE-2023-38497 is a high-severity (CVSS 7.9) CWE-278 vulnerability in cargo. A fix is available for cargo — see the affected versions and patch details below.
Cargo not respecting umask when extracting crate archives
Exploitation Status
No confirmed exploitation observed yet
- A successful exploit gives an attacker total control of the affected component, not partial access.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2023-38497.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2023-38497 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 378,567 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
cargoReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects crates.io packages — download data is not available via public APIs for these ecosystems.
Description
The Rust Security Response WG was notified that Cargo did not respect the umask when extracting crate archives on UNIX-like systems. If the user downloaded a crate containing files writeable by any local user, another local user could exploit this to change the source code compiled and executed by the current user.
This vulnerability has been assigned CVE-2023-38497.
Overview
In UNIX-like systems, each file has three sets of permissions: for the user owning the file, for the group owning the file, and for all other local users. The "umask" is configured on most systems to limit those permissions during file creation, removing dangerous ones. For example, the default umask on macOS and most Linux distributions only allow the user owning a file to write to it, preventing the group owning it or other local users from doing the same.
When a dependency is downloaded by Cargo, its source code has to be extracted on disk to allow the Rust compiler to read as part of the build. To improve performance, this extraction only happens the first time a dependency is used, caching the pre-extracted files for future invocations.
Unfortunately, it was discovered that Cargo did not respect the umask during extraction, and propagated the permissions stored in the crate archive as-is. If an archive contained files writeable by any user on the system (and the system configuration didn't prevent writes through other security measures), another local user on the system could replace or tweak the source code of a dependency, potentially achieving code execution the next time the project is compiled.
Affected Versions
All Rust versions before 1.71.1 on UNIX-like systems (like macOS and Linux) are affected. Note that additional system-dependent security measures configured on the local system might prevent the vulnerability from being exploited.
Users on Windows and other non-UNIX-like systems are not affected.
Mitigations
We recommend all users to update to Rust 1.71.1, which will be released later today, as it fixes the vulnerability by respecting the umask when extracting crate archives. If you build your own toolchain, patches for 1.71.0 source tarballs are available here.
To prevent existing cached extractions from being exploitable, the Cargo binary included in Rust 1.71.1 or later will purge the caches it tries to access if they were generated by older Cargo versions.
If you cannot update to Rust 1.71.1, we recommend configuring your system to prevent other local users from accessing the Cargo directory, usually located in ~/.cargo:
chmod go= ~/.cargo
Acknowledgments
We want to thank Addison Crump for responsibly disclosing this to us according to the Rust security policy.
We also want to thank the members of the Rust project who helped us disclose the vulnerability: Weihang Lo for developing the fix; Eric Huss for reviewing the fix; Pietro Albini for writing this advisory; Pietro Albini, Manish Goregaokar and Josh Stone for coordinating this disclosure; Josh Triplett, Arlo Siemen, Scott Schafer, and Jacob Finkelman for advising during the disclosure.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🦀crates.io | cargo | all versions | 0.72.2cargo update -p cargo --precise 0.72.2 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for cargo, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update cargo to 0.72.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-38497 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.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2023-38497 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2023-38497. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat Developer Tools | rust-toolset-1.66-rust-0:1.66.1-2.el7_9 | RHSA-2023:4651 |
| Red Hat Enterprise Linux 8 | rust-toolset:rhel8-8080020230807230209.0a78da64 | RHSA-2023:4635 |
| Red Hat Enterprise Linux 8.6 Extended Update Support | rust-toolset:rhel8-8060020240312174911.aeeed864 | RHSA-2024:3428 |
| Red Hat Enterprise Linux 9 | rust-0:1.66.1-2.el9_2 | RHSA-2023:4634 |
| Red Hat Enterprise Linux 9.0 Extended Update Support | rust-0:1.58.1-1.el9_0.1 | RHSA-2024:3418 |
Frequently Asked Questions
Is CVE-2023-38497 in your dependencies?
O3 Security finds CVE-2023-38497 across crates.io dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.