Security readout for executives and security teams
Plain-English summary
CVE-2021-35474 is a stack-based buffer overflow in the cachekey plugin for Apache Traffic Server. The listed affected versions are ATS 7.0.0-7.1.12, 8.0.0-8.1.1, and 9.0.0-9.0.1. The provided sources do not include CVSS, impact detail, or confirmed exploitation.
Executive priority
Treat this as a targeted infrastructure review item, especially for public-facing proxy services. Urgency is constrained by incomplete severity and exploitation evidence, but stack buffer overflows in edge infrastructure deserve timely validation and vendor-aligned remediation.
Technical view
The issue is classified as CWE-121 in Apache Traffic Server's cachekey plugin. A stack buffer overflow can affect process stability and may have stronger impact depending on reachable code paths, but the bundle does not provide exploitability details, prerequisites, or fixed version text.
Likely exposure
Exposure is likely limited to environments running the affected Apache Traffic Server versions with the cachekey plugin present or enabled. Asset owners should verify deployed ATS versions and plugin configuration rather than assuming all ATS deployments are affected.
Exploitation context
The bundle marks KEV as false and provides no cited evidence of active exploitation. It also does not include public exploit details, attack prerequisites, or whether remote unauthenticated triggering is confirmed.
Researcher notes
Key unknowns are trigger conditions, cachekey configuration requirements, fixed upstream versions, and practical impact. The CVE record supplies affected ranges and CWE classification, but not CVSS or exploitation detail. Validate against primary Apache and Debian advisory data.
Mitigation direction
- Check Apache and Debian advisories for fixed versions or package guidance.
- Upgrade affected Apache Traffic Server deployments according to vendor guidance.
- Prioritize internet-facing proxy and CDN edge deployments for review.
- Apply temporary exposure reduction where operationally feasible until remediation is confirmed.
Validation and detection
- Inventory Apache Traffic Server versions across proxy and edge systems.
- Confirm whether the cachekey plugin is installed or enabled.
- Compare deployments against affected ranges: 7.0.0-7.1.12, 8.0.0-8.1.1, 9.0.0-9.0.1.
- Review Debian DSA-4957 applicability for Debian-packaged Traffic Server.
- Document compensating controls if immediate upgrade is not possible.
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-121: 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 lookupCVE-2021-35474 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
- Unknown
- CVSS
- Not scored
- Known Exploited
- No
- Published
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 and timeline data
No CVSS vectors or timeline events were available in the normalized CVE source material.
Source materials
- CVE List V5 sourceCVE List V5
- https://lists.apache.org/thread.html/ra1a41ff92a70d25bf576d7da2590575e8ff430393a3f4a0c34de4277%40%3Cusers.trafficserver.apache.org%3ECVE reference · x_refsource_MISC
- DSA-4957CVE reference · vendor-advisory, x_refsource_DEBIAN
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.
Stack-based Buffer Overflow
Stack-based Buffer Overflow represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.