CVE-2021-21309
Summary
| CVE | CVE-2021-21309 |
|---|---|
| State | PUBLIC |
| Assigner | [email protected] |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2021-02-26 22:15:00 UTC |
| Updated | 2022-10-19 13:21:00 UTC |
| Description | Redis is an open-source, in-memory database that persists on disk. In affected versions of Redis an integer overflow bug in 32-bit Redis version 4.0 or newer could be exploited to corrupt the heap and potentially result with remote code execution. Redis 4.0 or newer uses a configurable limit for the maximum supported bulk input size. By default, it is 512MB which is a safe value for all platforms. If the limit is significantly increased, receiving a large request from a client may trigger several integer overflow scenarios, which would result with buffer overflow and heap corruption. We believe this could in certain conditions be exploited for remote code execution. By default, authenticated Redis users have access to all configuration parameters and can therefore use the “CONFIG SET proto-max-bulk-len” to change the safe default, making the system vulnerable. **This problem only affects 32-bit Redis (on a 32-bit system, or as a 32-bit executable running on a 64-bit system).** The problem is fixed in version 6.2, and the fix is back ported to 6.0.11 and 5.0.11. Make sure you use one of these versions if you are running 32-bit Redis. An additional workaround to mitigate the problem without patching the redis-server executable is to prevent clients from directly executing `CONFIG SET`: Using Redis 6.0 or newer, ACL configuration can be used to block the command. Using older versions, the `rename-command` configuration directive can be used to rename the command to a random string unknown to users, rendering it inaccessible. Please note that this workaround may have an additional impact on users or operational systems that expect `CONFIG SET` to behave in certain ways. |
Risk And Classification
Problem Types: CWE-190
NVD Known Affected Configurations (CPE 2.3)
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| Redis: Remote code execution (GLSA 202103-02) — Gentoo security | GENTOO | security.gentoo.org | |
| Integer overflow on 32-bit systems · Advisory · redis/redis · GitHub | CONFIRM | github.com | Third Party Advisory |
| Fix integer overflow. by yossigo · Pull Request #8522 · redis/redis · GitHub | MISC | github.com | Patch, Third Party Advisory |
| Fix integer overflow (CVE-2021-21309). (#8522) · redis/redis@c992857 · GitHub | MISC | github.com | Patch, Third Party Advisory |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
Legacy QID Mappings
- 180059 Debian Security Update for redis (CVE-2021-21309)
- 500599 Alpine Linux Security Update for redis
- 501481 Alpine Linux Security Update for redis
- 501774 Alpine Linux Security Update for redis
- 504353 Alpine Linux Security Update for redis
- 690241 Free Berkeley Software Distribution (FreeBSD) Security Update for redis (0e38b8f8-75dd-11eb-83f2-8c164567ca3c)
- 710008 Gentoo Linux Redis Remote Code Execution Vulnerability (GLSA 202103-02)
- 750019 SUSE Enterprise Linux Security Update for redis (SUSE-SU-2021:1652-1)
- 750226 OpenSUSE Security Update for redis (openSUSE-SU-2021:0682-1)
- 900042 CBL-Mariner Linux Security Update for redis 5.0.5
- 901260 Common Base Linux Mariner (CBL-Mariner) Security Update for redis (6843-1)
- 902996 Common Base Linux Mariner (CBL-Mariner) Security Update for redis (3923)