CVE-2021-32626 Lua scripts can overflow the heap-based Lua stack in Redis
Attackers can execute remote code by sending crafted Lua scripts that overflow the heap-based stack in Redis.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2021-32626?
CVE-2021-32626 is a high-severity memory corruption vulnerability in Debian Debian Linux, published on 4 Oct 2021. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
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.
Which versions are affected by CVE-2021-32626?
3 open source packages ship an affected version, including keydb, redis and valkey. It affects 6 products.
| Package | Affected | Fixed in |
|---|---|---|
keydb Bitnami | From 2.6.0 | 5.0.14, 6.0.16, 6.2.6 |
redis Bitnami | From 2.6.0 | 5.0.14, 6.0.16, 6.2.6 |
valkey Bitnami | From 2.6.0 | 5.0.14, 6.0.16, 6.2.6 |
Products include Debian Debian Linux, Fedoraproject Fedora, Netapp Management Services for Element Software, Netapp Management Services for Netapp Hci, Oracle Communications Operations Monitor, Redis Redis.
How do I fix CVE-2021-32626?
Upgrade keydb to a fixed version for your release line: 5.0.14, 6.0.16 or 6.2.6.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2021-32626 being exploited?
There is no known exploitation of CVE-2021-32626 in the wild and no public exploit code.
Other vulnerabilities in Debian Debian Linux
Sources
Also known as ALPINE-CVE-2021-32626, AZL-6844, BIT-keydb-2021-32626, BIT-redis-2021-32626, BIT-valkey-2021-32626, CLEANSTART-2026-QT24222 and 4 more.