Integer Overflow or Wraparound The advisory has been revoked - it doesn't affect any version of package hiredis (opens in a new tab)
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-UBUNTU1604-HIREDIS-1728272
- published1 Jun 2025
- disclosed4 Oct 2021
Introduced: 4 Oct 2021
CVE-2021-32765 (opens in a new tab)Amendment
The Ubuntu security team deemed this advisory irrelevant for Ubuntu:16.04.
NVD Description
Note: Versions mentioned in the description apply only to the upstream hiredis package and not the hiredis package as distributed by Ubuntu.
Hiredis is a minimalistic C client library for the Redis database. In affected versions Hiredis is vulnurable to integer overflow if provided maliciously crafted or corrupted RESP mult-bulk protocol data. When parsing multi-bulk (array-like) replies, hiredis fails to check if count * sizeof(redisReply*) can be represented in SIZE_MAX. If it can not, and the calloc() call doesn't itself make this check, it would result in a short allocation and subsequent buffer overflow. Users of hiredis who are unable to update may set the maxelements context option to a value small enough that no overflow is possible.
References
- http://people.ubuntu.com/~ubuntu-security/cve/CVE-2021-32765
- https://github.com/redis/hiredis/security/advisories/GHSA-hfm9-39pp-55p2
- https://github.com/redis/hiredis/commit/76a7b10005c70babee357a7d0f2becf28ec7ed1e
- https://wiki.sei.cmu.edu/confluence/display/c/MEM07-C.+Ensure+that+the+arguments+to+calloc%28%29%2C+when+multiplied%2C+do+not+wrap
- https://lists.debian.org/debian-lts-announce/2021/10/msg00007.html
- https://security.gentoo.org/glsa/202210-32
- https://security.netapp.com/advisory/ntap-20211104-0003/