CVE-2024-1135
python-gunicorn: HTTP Request Smuggling due to improper validation of Transfer-Encoding headers
Severity
ImportantRed Hat Product Security
CVSS 3.0
Review impact separately from score.
Published · April 15, 2024
Updated · November 1, 2026
Description
An HTTP Request Smuggling vulnerability was found in Gunicorn. By crafting requests with conflicting Transfer-Encoding headers, attackers can bypass security restrictions and access restricted endpoints. This issue is due to Gunicorn's handling of Transfer-Encoding headers, where it incorrectly processes requests with multiple, conflicting Transfer-Encoding headers, treating them as chunked regardless of the final encoding specified. This vulnerability allows for a range of attacks, including cache poisoning, session manipulation, and data exposure.
CVSS score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
Mitigation
Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update the affected package as soon as possible.
CVSS / CWE
CVSS 3.0 · 7.5CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
CWE-444 · Inconsistent Interpretation of HTTP Requests