Vulnerabilities > CVE-2021-32626 - Heap-based Buffer Overflow vulnerability in multiple products
Summary
Redis is an open source, in-memory database that persists on disk. In affected versions specially crafted Lua scripts executing in Redis can cause the heap-based Lua stack to be overflowed, due to incomplete checks for this condition. This can result with heap corruption and potentially remote code execution. This problem exists in all versions of Redis with Lua scripting support, starting from 2.6. The problem is fixed in versions 6.2.6, 6.0.16 and 5.0.14. For users unable to update an additional workaround to mitigate the problem without patching the redis-server executable is to prevent users from executing Lua scripts. This can be done using ACL to restrict EVAL and EVALSHA commands.
Vulnerable Configurations
Common Weakness Enumeration (CWE)
Common Attack Pattern Enumeration and Classification (CAPEC)
- Forced Integer Overflow This attack forces an integer variable to go out of range. The integer variable is often used as an offset such as size of memory allocation or similarly. The attacker would typically control the value of such variable and try to get it out of range. For instance the integer in question is incremented past the maximum possible value, it may wrap to become a very small, or negative number, therefore providing a very incorrect value which can lead to unexpected behavior. At worst the attacker can execute arbitrary code.
References
- https://github.com/redis/redis/commit/666ed7facf4524bf6d19b11b20faa2cf93fdf591
- https://github.com/redis/redis/security/advisories/GHSA-p486-xggp-782c
- https://security.netapp.com/advisory/ntap-20211104-0003/
- https://www.debian.org/security/2021/dsa-5001
- https://www.oracle.com/security-alerts/cpuapr2022.html
- https://security.gentoo.org/glsa/202209-17
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VL5KXFN3ATM7IIM7Q4O4PWTSRGZ5744Z/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/HTYQ5ZF37HNGTZWVNJD3VXP7I6MEEF42/
- https://lists.apache.org/thread.html/r75490c61c2cb7b6ae2c81238fd52ae13636c60435abcd732d41531a0%40%3Ccommits.druid.apache.org%3E
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WR5WKJWXD4D6S3DJCZ56V74ESLTDQRAB/