CVE-2021-31294Public exploitNetwork attack vector

Primary-server crash via replica keyspace command

Published Jul 15, 2023 · Updated Oct 30, 2024

Reachable assertion in Redis before commit 6cbea7d allows remote attackers controlling a replica connection to crash a primary server. The processCommand path exempts replica clients from the client write-pause check and accepts a SET or other keyspace command while failover has paused writes. A connection must first assume the replica role and initiate failover; the resulting failed assertion terminates the primary server and interrupts service.

CVSS severity5.9
Medium
EPSS probability1.31%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Reachable assertion in Redis before commit 6cbea7d allows remote attackers controlling a replica connection to crash a primary server. The processCommand path exempts replica clients from the client write-pause check and accepts a SET or other keyspace command while failover has paused writes. A connection must first assume the replica role and initiate failover; the resulting failed assertion terminates the primary server and interrupts service.

The record

CVE
CVE-2021-31294
Published
Jul 15, 2023
Updated
Oct 30, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-617, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 15, 2023CVE publishedPublication date reported by the CVE source.
  2. Oct 30, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

5.9NIST NVDCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/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.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-617Reachable Assertion
T1499.004Application or System Exploitation

Public exploit references

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

Technologies

Your stack

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Your stack

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