CVE-2017-16803 — In Libav through 11

In Libav through 11.11 and 12.x through 12.1, the smacker_decode_tree function in libavcodec/smacker.c does not properly restrict tree recursion, which allows remote attackers to cause a denial of service (bitstream.c:build_table() out-of-bounds read and application crash) via a

01What is this vulnerability?

In Libav through 11.11 and 12.x through 12.1, the smacker_decode_tree function in libavcodec/smacker.c does not properly restrict tree recursion, which allows remote attackers to cause a denial of service (bitstream.c:build_table() out-of-bounds read and application crash) via a crafted Smacker stream.

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

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: 2017-11-13T17:29:00.567
• Last modified: 2026-05-13T00:24:29.033

09References

• www.securityfocus.com — http://www.securityfocus.com/bid/101882
• bugzilla.libav.org — https://bugzilla.libav.org/show_bug.cgi?id=1098
• github.com — https://github.com/libav/libav/commit/cd4663dc80323ba64989d0c103d51ad3ee0e9c2f
• security.gentoo.org — https://security.gentoo.org/glsa/201811-19
• www.debian.org — https://www.debian.org/security/2018/dsa-4119
• www.securityfocus.com — http://www.securityfocus.com/bid/101882
• bugzilla.libav.org — https://bugzilla.libav.org/show_bug.cgi?id=1098
• github.com — https://github.com/libav/libav/commit/cd4663dc80323ba64989d0c103d51ad3ee0e9c2f
• security.gentoo.org — https://security.gentoo.org/glsa/201811-19
• www.debian.org — https://www.debian.org/security/2018/dsa-4119