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CVEs / CVE-2021-32761

CVE-2021-32761: redis redis vulnerability

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Description

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.

The CVE record, via NVD · published 21 Jul 2021 · NVD status: Modified

Affected and fixed versions

As stated by the CVE record (from the CNA)
ProductAffectedFixed in
redis redis>= 2.2, < 5.0.13—
redis redis>= 6.0.0, < 6.0.15—
redis redis>= 6.2.0, < 6.2.5—

Exploitation

Not in the CISA Known Exploited Vulnerabilities catalog as of 30 Oct 2026.

Severity

CVSS 3.17.5 high
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
Scored by NVD
WeaknessCWE-125, CWE-680, CWE-190

References

Sources

Exploitation status from the CISA Known Exploited Vulnerabilities catalog. EPSS scores from FIRST. Descriptions, severity and references from the National Vulnerability Database. Open-source package versions from OSV (CC-BY 4.0). Text is shown as each source states it; Stackurity does not edit it. Check the vendor's advisory before acting.

This product uses data from the NVD API but is not endorsed or certified by the NVD.