CVE-2021-32762

Integer overflow that can lead to heap overflow in redis-cli, redis-sentinel on some platforms

HIGH
8.8
CVSS Score
Published: October 4, 2021 at 06:00 PM UTC
Updated: June 17, 2026 at 03:53 AM UTC
6 products affected across 5 vendorsDebian LinuxFedoraRedis

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Severity
HIGH8.8
Exploit prediction
EPSS 3%

Description

Redis is an open source, in-memory database that persists on disk. The redis-cli command line tool and redis-sentinel service may be vulnerable to integer overflow when parsing specially crafted large multi-bulk network replies. This is a result of a vulnerability in the underlying hiredis library which does not perform an overflow check before calling the calloc() heap allocation function. This issue only impacts systems with heap allocators that do not perform their own overflow checks. Most modern systems do and are therefore not likely to be affected. Furthermore, by default redis-sentinel uses the jemalloc allocator which is also not vulnerable. The problem is fixed in Redis versions 6.2.6, 6.0.16 and 5.0.14.

Affected

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

v < 5.0.14v < 6.0.16v < 6.2.65.0.0 ≤ v < 5.0.146.0.0 ≤ v < 6.0.166.2.0 ≤ v < 6.2.6
Affected range stops below 5.0.14, so it looks safe — our inference, not a vendor statement
Affected range stops below 6.0.16, so it looks safe — our inference, not a vendor statement
Affected range stops below 6.2.6, so it looks safe — our inference, not a vendor statement

CVSS

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

Quick Info

StatusMODIFIED
CWE
CWE-190CWE-680

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