CVE-2017-9438 — libyara/re

libyara/re.c in the regexp module in YARA 3.5.0 allows remote attackers to cause a denial of service (stack consumption) via a crafted rule (involving hex strings) that is mishandled in the _yr_re_emit function, a different vulnerability than CVE-2017-9304.

01What is this vulnerability?

libyara/re.c in the regexp module in YARA 3.5.0 allows remote attackers to cause a denial of service (stack consumption) via a crafted rule (involving hex strings) that is mishandled in the _yr_re_emit function, a different vulnerability than CVE-2017-9304.

02Affected products

No structured affected-product list available — see references below for vendor advisories.

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

08Timeline

• Published: 2017-06-05T17:29:00.183
• Last modified: 2026-05-13T00:24:29.033

09References

• github.com — https://github.com/VirusTotal/yara/commit/10e8bd3071677dd1fa76beeef4bc2fc427cea5…
• github.com — https://github.com/VirusTotal/yara/issues/674
• lists.fedoraproject.org — https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro…
• lists.fedoraproject.org — https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro…
• github.com — https://github.com/VirusTotal/yara/commit/10e8bd3071677dd1fa76beeef4bc2fc427cea5…
• github.com — https://github.com/VirusTotal/yara/issues/674
• lists.fedoraproject.org — https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro…
• lists.fedoraproject.org — https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro…