Sereal::Decoder versions from 4.000 through 4.009_002 for Perl embeds a vulnerable version of the Zstandard library. Sereal::Decoder embeds a version of the Zstandard (zstd) library that is vulnerable to CVE-2019-11922. This is a race condition in the one-pass compression functions of Zstandard prior to version 1.3.8 could allow an attacker to write bytes out of bounds if an output buffer smaller than the recommended size was used.

• https://github.com/advisories/GHSA-w77f-wv46-4vcx
• https://www.cve.org/CVERecord?id=CVE-2019-11922
• https://metacpan.org/release/YVES/Sereal-Decoder-4.010/changes

In the Zstandard command-line utility prior to v1.4.1, output files were created with default permissions. Correct file permissions (matching the input) would only be set at completion time. Output files could therefore be readable or writable to unintended parties.

• https://www.facebook.com/security/advisories/cve-2021-24031
• https://github.com/facebook/zstd/issues/1630
• https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=981404