Summary
Details
When a tar stream contains multiple "header" entries prior to a file entry, astral-tokio-tar applies the PAX header (x) to the next entry in the stream, regardless of type. For example, a stream of x -> L -> file (PAX, GNU longname, file) would result in x's extensions being applied to L rather than to file.
Per POSIX pax, this is incorrect: a PAX header always applies to a file entry, not any intermediary entries. See the "pax Header Block" section for the specific prescription there.
As a result of this, an attacker can contrive a tar containing a sequence of tar headers such that astral-tokio-tar applies the PAX header's size extension to the next header in sequence, effectively desynchronizing the stream and enabling astral-tokio-tar specific skippage/extraction of members. In other words, a file can be contrived to extract differently on astral-tokio-tar than on other tar parsers.
Workarounds
Users are advised to upgrade to version 0.6.1 or newer to address this advisory.
There is no workaround other than upgrading. Users should experience no breaking changes as a result of the upgrade.
Resources
- GHSA-j5gw-2vrg-8fgx is a similar PAX desynchronization bug
- GHSA-fp55-jw48-c537 is another similar PAX desynchronization bug
Impact
Versions of astral-tokio-tar prior to 0.6.2 contain a PAX header interpretation bug that allows manipulated entries to be made selectively visible or invisible during extraction with astral-tokio-tar versus other tar implementations. An attacker could use this differential to smuggle unexpected files onto a victim's filesystem.
The application does not adequately validate input before processing it, allowing unexpected values to reach sensitive code paths. Typical impact: varies by context: data corruption, logic bypass, or denial of service.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
Remediation advice
Versions 0.6.2 and newer of astral-tokio-tar address this differential.
Frequently Asked Questions
- What is GHSA-3CV2-H65G-FGMM? GHSA-3CV2-H65G-FGMM is a medium-severity improper input validation vulnerability in astral-tokio-tar (rust), affecting versions <= 0.6.1. It is fixed in 0.6.2. The application does not adequately validate input before processing it, allowing unexpected values to reach sensitive code paths.
- Which versions of astral-tokio-tar are affected by GHSA-3CV2-H65G-FGMM? astral-tokio-tar (rust) versions <= 0.6.1 is affected.
- Is there a fix for GHSA-3CV2-H65G-FGMM? Yes. GHSA-3CV2-H65G-FGMM is fixed in 0.6.2. Upgrade to this version or later.
- Is GHSA-3CV2-H65G-FGMM exploitable, and should I be worried? Whether GHSA-3CV2-H65G-FGMM is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether GHSA-3CV2-H65G-FGMM is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix GHSA-3CV2-H65G-FGMM? Upgrade
astral-tokio-tarto 0.6.2 or later.