CVE & CISA-KEV Catalog

CVE-2021-32761

HIGHEPSS 98th pctl
7.5
CVSS v3
NVD

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.

How to fix

Remediation Available
redisDebian
Fixed in:5:6.0.15-1CVE-2021-32761
Fixed in:5:6.0.15-1CVE-2021-32761
Fixed in:5:6.0.15-1CVE-2021-32761
Fixed in:5:6.0.15-1CVE-2021-32761
redisUbuntu
Fixed in:2:2.8.4-2ubuntu0.2+esm2USN-5221-1
Fixed in:2:3.0.6-1ubuntu0.4+esm1USN-5221-1
Fixed in:5:4.0.9-1ubuntu0.2+esm3USN-5221-1
Fixed in:5:5.0.7-2ubuntu0.1+esm1USN-5221-1
redis-serverUbuntu
Fixed in:2:2.8.4-2ubuntu0.2+esm2USN-5221-1
Fixed in:2:3.0.6-1ubuntu0.4+esm1USN-5221-1
redis-toolsUbuntu
Fixed in:2:2.8.4-2ubuntu0.2+esm2USN-5221-1
Fixed in:2:3.0.6-1ubuntu0.4+esm1USN-5221-1
Fixed in:5:4.0.9-1ubuntu0.2+esm3USN-5221-1
Fixed in:5:5.0.7-2ubuntu0.1+esm1USN-5221-1

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Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork
Attack ComplexityHigh
Privileges RequiredLow
User InteractionNone
ScopeUnchanged

Impact

ConfidentialityHigh
IntegrityHigh
AvailabilityHigh

CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

Exploit Intelligence

31.05%probability of exploitation in 30 days
98thpercentile

Very high risk: more likely to be exploited than 98% of all known CVEs.

References

Related Vulnerabilities

Other CWE-125 (Out-of-bounds Read) vulnerabilities, ordered by exploit likelihood. View all

CVESeverityCVSSEPSSExploitedFix
CVE-2014-0160High7.5100%KEVFix
CVE-2025-5777High7.5100%KEV + RansomFix
CVE-2021-4034High7.895%KEVFix
CVE-2020-8794Critical9.889%-Fix
CVE-2023-49285High8.689%-Fix
CVE-2023-21769High7.589%-Fix

Common questions

How do I fix CVE-2021-32761?

Published advisories record a fix for 4 affected products. The "How to fix" section on this page lists the fixed version and source advisory for each one, so apply the entry matching what you actually run.

Is CVE-2021-32761 being actively exploited?

Not that we know of. CVE-2021-32761 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 31.0% is the estimated probability that it will be exploited in the next 30 days. That is higher than 98% of all scored CVEs.

How severe is CVE-2021-32761?

CVE-2021-32761 has a CVSS v3 base score of 7.5, rated high. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.

What does CVE-2021-32761 affect?

Published advisories record a fix for redis (Debian), redis (Ubuntu), redis-server (Ubuntu), redis-tools (Ubuntu). Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2024-11-21.