Security readout for executives and security teams
Plain-English summary
Traefik could let a specially crafted request cause a middleware-added request header to be dropped before reaching the backend. Business risk depends on whether that missing header can weaken authorization or trust decisions. The vendor patched this in 2.4.13 and lists no workaround besides upgrading.
Executive priority
Treat as a focused upgrade item, not an emergency, unless Traefik-added headers influence authentication or authorization in critical applications. Patch affected deployments during the next controlled maintenance window, prioritizing high-trust reverse proxy paths.
Technical view
Before Traefik 2.4.13, Connection header handling could remove a request header set by a Traefik middleware in a middleware chain. The backend then would not receive that header. The issue is classified as CWE-913 with CVSS 4.8, network reachable, high attack complexity, and low confidentiality and integrity impact.
Likely exposure
Exposure is likely limited to Traefik deployments older than 2.4.13, including legacy versions listed as <= 1.7.30, where middleware chains set request headers consumed by backends.
Exploitation context
The source bundle says active exploitation is unlikely because impact requires the removed header to enable privilege escalation. There is no KEV listing and no cited evidence of exploitation in the provided sources.
Researcher notes
Evidence supports a header-stripping flaw tied to Connection header processing and middleware-set request headers. Impact is environment-dependent. The provided sources do not establish exploitation, affected configurations beyond Traefik, or any mitigation other than upgrading.
Mitigation direction
- Upgrade Traefik to version 2.4.13 or later.
- Identify legacy 1.x deployments and check Traefik guidance for migration or support status.
- Prioritize systems where Traefik middleware adds headers used for authorization or trust decisions.
- Do not rely on unverified workarounds; the source lists none besides upgrading.
Validation and detection
- Inventory Traefik versions across internet-facing and internal reverse proxy deployments.
- Review middleware chains that set request headers before forwarding to backends.
- Confirm whether backends depend on middleware-added headers for access control decisions.
- Verify upgraded systems report Traefik 2.4.13 or later.
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-913: 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 lookupPrivilege behavior lookup
The CVE wording references privilege impact, so privilege escalation and authorization behavior review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2021-32813 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
- Medium
- CVSS
- 4.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N
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:N/UI:N/S:U/C:L/I:L/A:N2.22.5Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
4.8MediumVector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/traefik/traefik/security/advisories/GHSA-m697-4v8f-55qgCVE reference · x_refsource_CONFIRM
- https://github.com/traefik/traefik/pull/8319/commits/cbaf86a93014a969b8accf39301932c17d0d73f9CVE reference · x_refsource_MISC
- https://github.com/traefik/traefik/releases/tag/v2.4.13CVE reference · x_refsource_MISC
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.
Improper Control of Dynamically-Managed Code Resources
Improper Control of Dynamically-Managed Code Resources represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.