CVE-2018-19975 — In YARA 3

In YARA 3.8.1, bytecode in a specially crafted compiled rule can read data from any arbitrary address in memory, in libyara/exec.c. Specifically, OP_COUNT can read a DWORD.

01What is this vulnerability?

In YARA 3.8.1, bytecode in a specially crafted compiled rule can read data from any arbitrary address in memory, in libyara/exec.c. Specifically, OP_COUNT can read a DWORD.

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

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: 2018-12-17T18:00:00.000Z
• Last modified: 2024-08-05T11:51:17.938Z

09References

• bnbdr.github.io — https://bnbdr.github.io/posts/extracheese/
• github.com — https://github.com/VirusTotal/yara/issues/999
• github.com — https://github.com/bnbdr/swisscheese/
• lists.fedoraproject.org — https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro…