Unintended leak of Proxy-Authorization header in requests
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Fix
- Fixed in 2.31.0
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- 2 proofs of concept on GitHub
- Exploitation: none
- Automatable: no
- Technical impact: partial
Summary
Requests is a HTTP library. Since Requests 2.3.0, Requests has been leaking Proxy-Authorization headers to destination servers when redirected to an HTTPS endpoint. This is a product of how we use `rebuild_proxies` to reattach the `Proxy-Authorization` header to requests. For HTTP connections sent through the tunnel, the proxy will identify the header in the request itself and remove it prior to forwarding to the destination server. However when sent over HTTPS, the `Proxy-Authorization` header must be sent in the CONNECT request as the proxy has no visibility into the tunneled request. This results in Requests forwarding proxy credentials to the destination server unintentionally, allowing a malicious actor to potentially exfiltrate sensitive information. This issue has been patched in version 2.31.0.
Timeline
- CVE published
- CISA SSVC assessment
Exploitation: none · Automatable: no · Technical impact: partial
- Record last updated
Affected versions
- psf requests
From 2.3.0 · fixed in 2.31.0
- requestsPyPI
From 2.3.0 · fixed in 2.31.0