CVE-2023-29420 — An issue was discovered in libbzip3

An issue was discovered in libbzip3.a in bzip3 before 1.2.3. There is a crash caused by an invalid memmove in bz3_decode_block.

01What is this vulnerability?

An issue was discovered in libbzip3.a in bzip3 before 1.2.3. There is a crash caused by an invalid memmove in bz3_decode_block.

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: 2023-04-06T00:00:00.000Z
• Last modified: 2025-03-05T19:00:53.819Z

09References

• github.com — https://github.com/kspalaiologos/bzip3/issues/92
• github.com — https://github.com/kspalaiologos/bzip3/compare/1.2.2...1.2.3
• github.com — https://github.com/kspalaiologos/bzip3/commit/bb06deb85f1c249838eb938e0dab271d41…
• 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…
• lists.fedoraproject.org — https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro…