CVE-2019-5601 — In FreeBSD 12

In FreeBSD 12.0-STABLE before r347474, 12.0-RELEASE before 12.0-RELEASE-p7, 11.2-STABLE before r347475, and 11.2-RELEASE before 11.2-RELEASE-p11, a bug in the FFS implementation causes up to three bytes of kernel stack memory to be written to disk as uninitialized directory entry

01What is this vulnerability?

In FreeBSD 12.0-STABLE before r347474, 12.0-RELEASE before 12.0-RELEASE-p7, 11.2-STABLE before r347475, and 11.2-RELEASE before 11.2-RELEASE-p11, a bug in the FFS implementation causes up to three bytes of kernel stack memory to be written to disk as uninitialized directory entry padding.

02Affected products

Vendor	Product	Versions
FreeBSD	FreeBSD	FreeBSD 12.0 before 12.0-RELEASE-p7 and 11.2 before 11.2-RELEASE-p11

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

Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.

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: 2019-07-03T18:51:47.000Z
• Last modified: 2024-08-04T20:01:52.130Z

09References

• security.FreeBSD.org — https://security.FreeBSD.org/advisories/FreeBSD-SA-19:10.ufs.asc
• packetstormsecurity.com — http://packetstormsecurity.com/files/153523/FreeBSD-Security-Advisory-FreeBSD-SA…