CVE-2023-39804 — In GNU tar before 1

In GNU tar before 1.35, mishandled extension attributes in a PAX archive can lead to an application crash in xheader.c.

01What is this vulnerability?

In GNU tar before 1.35, mishandled extension attributes in a PAX archive can lead to an application crash in xheader.c.

02Affected products

Vendor	Product	Versions
n	a / n/a	n/a

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Open the Sigma generator with a pre-filled prompt for this CVE to draft a starting detection in your stack of choice:

Open in Sigma generator →

07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2024-03-27T00:00:00.000Z
• Last modified: 2025-11-04T18:16:37.208Z

09References

• git.savannah.gnu.org — https://git.savannah.gnu.org/cgit/tar.git/commit/?id=a339f05cd269013fa133d2f148d…
• git.savannah.gnu.org — https://git.savannah.gnu.org/cgit/tar.git/tree/src/xheader.c?h=release_1_34#n172…
• bugs.debian.org — https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1058079