CVE-2019-20397 — A double-free is present in libyang before v1
A double-free is present in libyang before v1.0-r1 in the function yyparse() when an organization field is not terminated. Applications that use libyang to parse untrusted input yang files may be vulnerable to this flaw, which would cause a crash or potentially code execution.
Published
2020-01-22T00:00:00.000Z
Last modified
2024-08-05T02:39:09.895Z
01What is this vulnerability?
A double-free is present in libyang before v1.0-r1 in the function yyparse() when an organization field is not terminated. Applications that use libyang to parse untrusted input yang files may be vulnerable to this flaw, which would cause a crash or potentially code execution.
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: 2020-01-22T00:00:00.000Z
- Last modified: 2024-08-05T02:39:09.895Z
09References
- github.com — https://github.com/CESNET/libyang/compare/v0.16-r3...v1.0-r1
- github.com — https://github.com/CESNET/libyang/issues/739
- github.com — https://github.com/CESNET/libyang/commit/88bd6c548ba79bce176cd875e9b56e7e0ef4d8d…
- bugzilla.redhat.com — https://bugzilla.redhat.com/show_bug.cgi?id=1793928
- lists.debian.org — https://lists.debian.org/debian-lts-announce/2023/09/msg00019.html
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