Coder: Workspace agent API insecure redirect handling allowed cross-agent file read and write
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- High · High · Low
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-863.
Summary
Coder allows organizations to provision remote development environments via Terraform. Prior to 2.29.19, 2.32.9, 2.33.10, and 2.34.4, agentConn.apiClient() follows redirects while its custom transport accepts the host from the redirected request URL when the port is the workspace agent HTTP API port 4. An authenticated user who controls a modified workspace agent and knows another online agent's UUID can derive the victim's tailnet address and redirect control-plane requests to that agent. HTTP 301, 302, and 303 redirects can redirect read requests, while HTTP 307 and 308 preserve replayable write and process-start requests. The redirected workspace agent file APIs can read or write files as the victim workspace user, and affected versions exposing the workspace agent process API can execute commands after a redirected file write, crossing workspace and tenant boundaries. This issue is fixed in versions 2.29.19, 2.32.9, 2.33.10, and 2.34.4.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| coder | coder | 2.27.0 to before 2.29.19; 2.30.0 to before 2.32.9; 2.33.0 to before 2.33.10; 2.34.0 to before 2.34.4 | 2.29.19, 2.32.9, 2.33.10, 2.34.4 | Patch available | CNA |
- coder Vendorcoder Affected 2.27.0 to before 2.29.19; 2.30.0 to before 2.32.9; 2.33.0 to before 2.33.10; 2.34.0 to before 2.34.4 Fixed in 2.29.19, 2.32.9, 2.33.10, 2.34.4 Patch available CNA
Remediation
- Fix · CNA coder (coder) Fixed in 2.29.19, 2.32.9, 2.33.10, 2.34.4
Timeline
- 2026-10-02 Threatist record created from CVE-2026-63443
References
Other 15
- https://github.com/coder/coder/security/advisories/GHSA-qrwj-vh9x-gw5v
- https://github.com/coder/coder/pull/26600
- https://github.com/coder/coder/pull/26611
- https://github.com/coder/coder/pull/26612
- https://github.com/coder/coder/pull/26613
- https://github.com/coder/coder/pull/26622
- https://github.com/coder/coder/commit/2312b67bc52c4e314c18c4b4be5dcf5500c94ad7
- https://github.com/coder/coder/commit/812549d671d0f5a0b45adcee860d37b70aaddccd
- https://github.com/coder/coder/commit/ec3ba84c0002f47dd979c073cde1ab345acbaea5
- https://github.com/coder/coder/commit/eeb2624549ddb85538e493af3e678fdb185a809f
- https://github.com/coder/coder/commit/f8bdec5add4711650d5bfb6ff93d0cc9d7821c81
- https://github.com/coder/coder/releases/tag/v2.29.19
- https://github.com/coder/coder/releases/tag/v2.32.9
- https://github.com/coder/coder/releases/tag/v2.33.10
- https://github.com/coder/coder/releases/tag/v2.34.4
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Sources
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences