CVE-2021-32625Network attack vector

Remote code execution via LCS table overflow

Published Jun 2, 2021 · Updated Aug 3, 2024

Integer overflow in Redis 6.0.0 through 6.0.13 and 6.2.0 through 6.2.3 allows remote authenticated users to corrupt the heap. The stralgoLCS function multiplies untrusted string lengths to size a uint32_t LCS table in size_t without detecting wraparound, then writes through the undersized allocation. Command access and oversized strings are required; heap corruption can crash the service or execute code, while 64-bit builds with the prior fix are exposed only when proto-max-bulk-len is at least 2 GB.

CVSS severity7.5
High
EPSS probability4.26%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Integer overflow in Redis 6.0.0 through 6.0.13 and 6.2.0 through 6.2.3 allows remote authenticated users to corrupt the heap. The stralgoLCS function multiplies untrusted string lengths to size a uint32_t LCS table in size_t without detecting wraparound, then writes through the undersized allocation. Command access and oversized strings are required; heap corruption can crash the service or execute code, while 64-bit builds with the prior fix are exposed only when proto-max-bulk-len is at least 2 GB.

The record

CVE
CVE-2021-32625
Published
Jun 2, 2021
Updated
Aug 3, 2024
Vendor
Redis
Product
Redis
Classifications
CWE-680, T1210
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 2, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 6.0.14
  2. Affected versionversion=>= 6.2.0, < 6.2.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Redis · Redisversion=< 6.0.14; version=>= 6.2.0, < 6.2.4

Published CVSS scores

7.5GitHub Security AdvisoryCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-680Integer Overflow to Buffer Overflow
T1210Exploitation of Remote Services

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo