CVE-2021-32761

Integer overflow issues with *BIT commands on 32-bit systems

HIGH
7.5
CVSS Score
Published: July 21, 2021 at 08:50 PM UTC
Updated: June 17, 2026 at 03:53 AM UTC
3 products affected across 3 vendorsDebian LinuxFedoraRedis

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Severity
HIGH7.5
Exploit prediction
EPSS 37%

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 5.0.13v < 6.0.15v < 6.2.52.2.0 ≤ v < 5.0.136.0 ≤ v < 6.0.156.2.0 ≤ v < 6.2.5
Affected range stops below 5.0.13, so it looks safe — our inference, not a vendor statement
Affected range stops below 6.0.15, so it looks safe — our inference, not a vendor statement
Affected range stops below 6.2.5, so it looks safe — our inference, not a vendor statement

CVSS

7.5HIGHGitHub_M
Attack Vector
NETWORK
Complexity
HIGH
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-125CWE-680CWE-190

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