Security readout for executives and security teams
Plain-English summary
A flaw in Redis can let an authorized client misuse the STRALGO LCS command to corrupt memory. The vendor says this could potentially lead to remote code execution. Exposure is limited to Redis 6.0 and 6.2 versions before the fixed releases.
Executive priority
Prioritize remediation for internet-reachable or broadly shared Redis services where many applications or users have Redis access. Treat this as high urgency for affected versions because the vendor describes potential remote code execution, despite no cited active exploitation.
Technical view
CVE-2021-29477 is a CWE-190 integer overflow in Redis 6.0.0-6.0.12 and 6.2.0-6.2.2. The issue is reachable through STRALGO LCS and may corrupt heap memory. CVSS is 7.5 with network access, low privileges, no user interaction, and high attack complexity.
Likely exposure
Likely exposure exists where Redis 6.0.x or 6.2.x runs below 6.0.13 or 6.2.3 and clients can execute STRALGO LCS. The CVSS vector requires low privileges, so the bundle does not support treating this as unauthenticated exposure.
Exploitation context
The source bundle does not report active exploitation, and KEV is false. The issue is still serious because successful exploitation could affect confidentiality, integrity, and availability, but the cited CVSS vector marks attack complexity as high.
Researcher notes
Do not assume all Redis versions are affected. The bundle names only Redis 6.0.0-6.0.12 and 6.2.0-6.2.2. Validation should focus on version, client authorization to STRALGO LCS, and whether distro packages include the upstream fix.
Mitigation direction
- Upgrade Redis 6.2.x to 6.2.3 or later.
- Upgrade Redis 6.0.x to 6.0.13 or later.
- Use Redis ACLs to block client use of STRALGO LCS if patching is delayed.
- For packaged Redis, apply relevant Fedora or Gentoo security updates.
- Check current Redis vendor guidance before relying on workarounds.
Validation and detection
- Inventory Redis deployments and record exact server versions.
- Flag Redis 6.0.0-6.0.12 and 6.2.0-6.2.2 as affected.
- Confirm STRALGO LCS is blocked for clients when using the ACL workaround.
- Verify package versions against Fedora or Gentoo advisories where applicable.
- Confirm production Redis instances are on fixed versions after remediation.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-190: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupExecution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupDatabase behavior lookup
The CVE wording references database injection or access, so collection and exfiltration review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2021-29477 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 7.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H1.65.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
7.5HighVector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/redis/redis/security/advisories/GHSA-vqxj-26vj-996gCVE reference · x_refsource_CONFIRM
- https://redis.io/CVE reference · x_refsource_MISC
- FEDORA-2021-3b267a756cCVE reference · vendor-advisory, x_refsource_FEDORA
- FEDORA-2021-8b19c99d6aCVE reference · vendor-advisory, x_refsource_FEDORA
- FEDORA-2021-916f861096CVE reference · vendor-advisory, x_refsource_FEDORA
- FEDORA-2021-0ad4bec5b1CVE reference · vendor-advisory, x_refsource_FEDORA
- GLSA-202107-20CVE reference · vendor-advisory, x_refsource_GENTOO
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.