ALPINE-CVE-2021-32761
Redis is an in-memory database that persists on disk. A vulnerability involving out-of-bounds read and integer overflow to buffer overflow exists starting with version 2.2 and prior to versions 5.0.13, 6.0.15, and 6.2.5. On 32-bit systems, Redis `*BIT*` command are vulnerable to integer overflow that can potentially be exploited to corrupt the heap, leak arbitrary heap contents or trigger remote code execution. The vulnerability involves changing the default `proto-max-bulk-len` configuration parameter to a very large value and constructing specially crafted commands bit commands. This problem only affects Redis on 32-bit platforms, or compiled as a 32-bit binary. Redis versions 5.0.`3m 6.0.15, and 6.2.5 contain patches for this issue. An additional workaround to mitigate the problem without patching the `redis-server` executable is to prevent users from modifying the `proto-max-bulk-len` configuration parameter. This can be done using ACL to restrict unprivileged users from using the CONFIG SET command.
Risk Scores
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Alpine:v3.16 | redis | 4.0.9-r0, 6.2.4-r0, 6.2.3-r0 |
| Alpine:v3.13 | redis | 4.0.11-r0, 3.2.5-r0, 0 |
| Alpine:v3.14 | redis | 4.0.12-r0, 4.0.13-r0, 4.0.2-r0 |
| Alpine:v3.19 | redis | 2.4.14-r1, 0, 2.4.14-r0 |
| Alpine:v3.12 | redis | 2.8.14-r0, 2.8.10-r0, 2.8.14-r0 |
| Alpine:v3.17 | redis | 2.8.14-r0, 2.8.17-r0, 2.8.19-r0 |
| Alpine:v3.11 | redis | 0, 5.0.7-r1, 5.0.7-r0 |
| Alpine:v3.15 | redis | 3.0.7-r0, 3.0.7-r1, 3.2.4-r0 |
| Alpine:v3.18 | redis | 0, 2.4.14-r1, 2.4.16-r0 |
Timeline
- Jul 21, 2021 CVE Published
- Nov 19, 2025 CVE Updated
- Apr 30, 2026 Distribution Patch