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.
The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.
| Link | Tags |
|---|---|
| https://github.com/redis/hiredis/security/advisories/GHSA-hfm9-39pp-55p2 | mitigation third party advisory |
| https://github.com/redis/hiredis/commit/76a7b10005c70babee357a7d0f2becf28ec7ed1e | third party advisory patch |
| 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 | third party advisory |
| https://lists.debian.org/debian-lts-announce/2021/10/msg00007.html | third party advisory mailing list |
| https://security.netapp.com/advisory/ntap-20211104-0003/ | third party advisory |
| https://security.gentoo.org/glsa/202210-32 | third party advisory vendor advisory |