CVE-2021-32765

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](https://github.com/redis/hiredis#reader-max-array-elements) context option to a value small enough that no overflow is possible.

• CWE-190
• CWE-680
• CWE-190

• https://github.com/redis/hiredis/commit/76a7b10005c70babee357a7d0f2becf28ec7ed1ePatch, Third Party Advisory
• https://github.com/redis/hiredis/security/advisories/GHSA-hfm9-39pp-55p2Mitigation, Third Party Advisory
• https://lists.debian.org/debian-lts-announce/2021/10/msg00007.htmlMailing List, Third Party Advisory
• https://security.gentoo.org/glsa/202210-32Third Party Advisory
• https://security.netapp.com/advisory/ntap-20211104-0003/Third Party Advisory
• https://wiki.sei.cmu.edu/confluence/display/c/MEM07-C.+Ensure+that+the+arguments+to+calloc%28%29%2C+when+multiplied%2C+do+not+wrapThird Party Advisory
• https://github.com/redis/hiredis/commit/76a7b10005c70babee357a7d0f2becf28ec7ed1ePatch, Third Party Advisory
• https://github.com/redis/hiredis/security/advisories/GHSA-hfm9-39pp-55p2Mitigation, Third Party Advisory
• https://lists.debian.org/debian-lts-announce/2021/10/msg00007.htmlMailing List, Third Party Advisory
• https://security.gentoo.org/glsa/202210-32Third Party Advisory
• https://security.netapp.com/advisory/ntap-20211104-0003/Third Party Advisory
• https://wiki.sei.cmu.edu/confluence/display/c/MEM07-C.+Ensure+that+the+arguments+to+calloc%28%29%2C+when+multiplied%2C+do+not+wrapThird Party Advisory

Published

Oct 4, 2021

Last Modified

Jun 17, 2026

Status

Modified