CVE-2021-32675DoS vulnerability in Redis
- 7.5HighCVSS base score
- 16.1%Exploitation in 30 daysEPSS · top 3.0% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
Redis is an open source, in-memory database that persists on disk. When parsing an incoming Redis Standard Protocol (RESP) request, Redis allocates memory according to user-specified values which determine the number of elements (in the multi-bulk header) and size of each element (in the bulk header). An attacker delivering specially crafted requests over multiple connections can cause the server to allocate significant amount of memory. Because the same parsing mechanism is used to handle authentication requests, this vulnerability can also be exploited by unauthenticated users. The problem is fixed in Redis versions 6.2.6, 6.0.16 and 5.0.14. An additional workaround to mitigate this problem without patching the redis-server executable is to block access to prevent unauthenticated users from connecting to Redis. This can be done in different ways: Using network access control tools like firewalls, iptables, security groups, etc. or Enabling TLS and requiring users to authenticate using client side certificates.
Timeline
ID reserved
By GitHub_M
- 5 months later
· 5 months later
Published
- 3 years later
· 3 years later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | High7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| NVDNVD · Modified | 3.1 | High7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
- EPSS (exploitation in 30 days)
- 16.1% · top 3.0% of all CVEs (13 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.5.
Affected products
References
References10
- https://github.com/redis/redis/security/advisories/GHSA-f6pw-v9gw-v64p (opens in a new tab)x_refsource_CONFIRMx_transferred
- https://github.com/redis/redis/commit/5674b0057ff2903d43eaff802017eddf37c360f8 (opens in a new tab)x_refsource_MISCx_transferred
- FEDORA-2021-8913c7900c (opens in a new tab)vendor-advisoryx_refsource_FEDORAx_transferred
- FEDORA-2021-61c487f241 (opens in a new tab)vendor-advisoryx_refsource_FEDORAx_transferred
- [geode-notifications] 20211013 [GitHub] [geode] jdeppe-pivotal opened a new pull request #6994: GEODE-9676: Limit array and string sizes for unauthenticated Radish connections (opens in a new tab)mailing-listx_refsource_MLISTx_transferred
- FEDORA-2021-aa94492a09 (opens in a new tab)vendor-advisoryx_refsource_FEDORAx_transferred
- DSA-5001 (opens in a new tab)vendor-advisoryx_refsource_DEBIANx_transferred
- https://www.oracle.com/security-alerts/cpuapr2022.html (opens in a new tab)x_refsource_MISCx_transferred
- https://security.netapp.com/advisory/ntap-20211104-0003/ (opens in a new tab)x_refsource_CONFIRMx_transferred
- GLSA-202209-17 (opens in a new tab)vendor-advisoryx_refsource_GENTOOx_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2021-19484 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2021-32675)Record last updated .