How severe is CVE-2021-29477?

CVE-2021-29477 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with high attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-29477 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (89th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-29477?

CVE-2021-29477 primarily affects Redislabs Redis. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-29477?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2021-29477 published?

CVE-2021-29477 was published on 2021-05-04 and last updated on 2026-06-17.

CVE-2021-29477

CVE-2021-29477 is a high-severity vulnerability in Redislabs Redis with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-190.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 6.5
EPSS exploit prediction: 4% (89th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-190
Affected product: Redislabs Redis
Published: 2021-05-04
Last modified: 2026-06-17

Description

Redis is an open source (BSD licensed), in-memory data structure store, used as a database, cache, and message broker. An integer overflow bug in Redis version 6.0 or newer could be exploited using the `STRALGO LCS` command to corrupt the heap and potentially result with remote code execution. The problem is fixed in version 6.2.3 and 6.0.13. An additional workaround to mitigate the problem without patching the redis-server executable is to use ACL configuration to prevent clients from using the `STRALGO LCS` command.

Frequently asked questions

What is CVE-2021-29477?: Redis is an open source (BSD licensed), in-memory data structure store, used as a database, cache, and message broker. An integer overflow bug in Redis version 6.0 or newer could be exploited using the `STRALGO LCS` command to corrupt the heap and potentially result with remote code execution. The problem is fixed in version 6.2.3 and 6.0.13. An additional workaround to mitigate the problem without patching the redis-server executable is to use ACL configuration to prevent clients from using the `STRALGO LCS` command.
How severe is CVE-2021-29477?: CVE-2021-29477 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with high attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-29477 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (89th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-29477?: CVE-2021-29477 primarily affects Redislabs Redis. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-29477?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-29477 published?: CVE-2021-29477 was published on 2021-05-04 and last updated on 2026-06-17.

References

Affected products (3)

cpe:2.3:a:redislabs:redis:*:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*

More vulnerabilities in Redislabs Redis

CVE-2015-4335 — Critical (CVSS 10.0): Redis before 2.8.21 and 3.x before 3.0.2 allows remote attackers to execute arbitrary Lua bytecode via the eval command.
CVE-2018-11219 — Critical (CVSS 9.8): An Integer Overflow issue was discovered in the struct library in the Lua subsystem in Redis before 3.2.12, 4.x before…
CVE-2018-11218 — Critical (CVSS 9.8): Memory Corruption was discovered in the cmsgpack library in the Lua subsystem in Redis before 3.2.12, 4.x before…
CVE-2017-15047 — Critical (CVSS 9.8): The clusterLoadConfig function in cluster.c in Redis 4.0.2 allows attackers to cause a denial of service (out-of-bounds…
CVE-2016-8339 — Critical (CVSS 9.8): A buffer overflow in Redis 3.2.x prior to 3.2.4 causes arbitrary code execution when a crafted command is sent. An out…
CVE-2018-12326 — High (CVSS 8.4): Buffer overflow in redis-cli of Redis before 4.0.10 and 5.x before 5.0 RC3 allows an attacker to achieve code execution…

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Other CWE-190 (Integer Overflow or Wraparound) vulnerabilities

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