CVE-2023-45803 Information

Description

urllib3 is a user-friendly HTTP client library for Python. urllib3 previously wouldn’t remove the HTTP request body when an HTTP redirect response using status 301 302 or 303 after the request had its method changed from one that could accept a request body (like POST) to GET as is required by HTTP RFCs. Although this behavior is not specified in the section for redirects it can be inferred by piecing together information from different sections and we have observed the behavior in other major HTTP client implementations like curl and web browsers. Because the vulnerability requires a previously trusted service to become compromised in order to have an impact on confidentiality we believe the exploitability of this vulnerability is low. Additionally many users aren’t putting sensitive data in HTTP request bodies if this is the case then this vulnerability isn’t exploitable. Both of the following conditions must be true to be affected by this vulnerability: 1. Using urllib3 and submitting sensitive information in the HTTP request body (such as form data or JSON) and 2. The origin service is compromised and starts redirecting using 301 302 or 303 to a malicious peer or the redirected-to service becomes compromised. This issue has been addressed in versions 1.26.18 and 2.0.7 and users are advised to update to resolve this issue. Users unable to update should disable redirects for services that aren’t expecting to respond with redirects with redirects=False and disable automatic redirects with redirects=False and handle 301 302 and 303 redirects manually by stripping the HTTP request body.

Reference

https://github.com/urllib3/urllib3/security/advisories/GHSA-g4mx-q9vg-27p4 https://github.com/urllib3/urllib3/security/advisories/GHSA-g4mx-q9vg-27p4 https://www.rfc-editor.org/rfc/rfc9110.html#name-get https://github.com/urllib3/urllib3/commit/4e98d57809dacab1cbe625fddeec1a290c478ea9 https://github.com/urllib3/urllib3/commit/4e98d57809dacab1cbe625fddeec1a290c478ea9 urllib3 is a user-friendly HTTP client library for Python. urllib3 previously wouldn’t remove the HTTP request body when an HTTP redirect response using status 301 302 or 303 after the request had its method changed from one that could accept a request body (like POST) to GET as is required by HTTP RFCs. Although this behavior is not specified in the section for redirects it can be inferred by piecing together information from different sections and we have observed the behavior in other major HTTP client implementations like curl and web browsers. Because the vulnerability requires a previously trusted service to become compromised in order to have an impact on confidentiality we believe the exploitability of this vulnerability is low. Additionally many users aren’t putting sensitive data in HTTP request bodies if this is the case then this vulnerability isn’t exploitable. Both of the following conditions must be true to be affected by this vulnerability: 1. Using urllib3 and submitting sensitive information in the HTTP request body (such as form data or JSON) and 2. The origin service is compromised and starts redirecting using 301 302 or 303 to a malicious peer or the redirected-to service becomes compromised. This issue has been addressed in versions 1.26.18 and 2.0.7 and users are advised to update to resolve this issue. Users unable to update should disable redirects for services that aren’t expecting to respond with redirects with redirects=False and disable automatic redirects with redirects=False and handle 301 302 and 303 redirects manually by stripping the HTTP request body.