Debian Security Advisory

DLA-2783-1 hiredis -- LTS security update

Date Reported:
12 Oct 2021
Affected Packages:
Security database references:
In Mitre's CVE dictionary: CVE-2021-32765.
More information:

It was discovered that there was an integer-overflow vulnerability in hiredis, a C client library for communicating with Redis databases. This occurred within the handling and parsing of 'multi-bulk' replies.

  • 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]( context option to a value small enough that no overflow is possible.

For Debian 9 Stretch, these problems have been fixed in version 0.13.3-1+deb9u1.

We recommend that you upgrade your hiredis packages.

Further information about Debian LTS security advisories, how to apply these updates to your system and frequently asked questions can be found at: