8.7 HIGH
- CVSS version (CVSS): 4.0
- Attack Vector (AV): Network (N)
- Attack Complexity (AC): Low (L)
- Attack Requirement (AT): None (N)
- Privileges Required (PR): None (N)
- User Interaction (UI): None (N)
- Vulnerable System Impact Confidentiality (VC): None (N)
- Vulnerable System Impact Integrity (VI): None (N)
- Vulnerable System Impact Availability (VA): High (H)
- Subsequent System Impact Confidentiality (SC): None (N)
- Subsequent System Impact Integrity (SI): None (N)
- Subsequent System Impact Availability (SA): None (N)
- Modified Attack Vector (MAV): Network (N)
- Modified Attack Complexity (MAC): Low (L)
- Modified Attack Requirement (MAT): None (N)
- Modified Privileges Required (MPR): None (N)
- Modified User Interaction (MUI): None (N)
- Modified Vulnerable System Impact Confidentiality (MVC): None (N)
- Modified Vulnerable System Impact Integrity (MVI): None (N)
- Modified Vulnerable System Impact Availability (MVA): High (H)
- Modified Subsequent System Impact Confidentiality (MSC): Negligible (N)
- Modified Subsequent System Impact Integrity (MSI): Negligible (N)
- Modified Subsequent System Impact Availability (MSA): Negligible (N)
- Safety (S): Not Defined (X)
- Automatable (AU): Not Defined (X)
- Recovery (R): Not Defined (X)
- Value Density (V): Not Defined (X)
- Vulnerability Response Effort (RE): Not Defined (X)
- Provider Urgency (U): Not Defined (X)
- Confidentiality Req. (CR): Not Defined (X)
- Integrity Req. (IR): Not Defined (X)
- Availability Req. (AR): Not Defined (X)
- Exploit Maturity (E): Not Defined (X)
Activity log
- Created suggestion
HTTP/1 chunked decoder infinite loop on requests with trailer fields in bandit
Loop with Unreachable Exit Condition ('Infinite Loop') vulnerability in mtrudel bandit allows unauthenticated remote denial of service via worker process exhaustion. 'Elixir.Bandit.HTTP1.Socket':do_read_chunked_data!/5 in lib/bandit/http1/socket.ex terminates only when the last-chunk line 0\r\n is followed immediately by the empty trailer line \r\n. RFC 9112 §7.1.2 permits zero or more trailer fields between them. When trailers are present, none of the match clauses fit: the catch-all arm computes a negative to_read, calls read_available!/2, receives <<>> on timeout, and tail-recurses with unchanged state. The worker process is pinned for the lifetime of the TCP connection. A handful of concurrent connections sending RFC-conformant chunked requests with trailer fields is sufficient to exhaust the Bandit worker pool and render the server unresponsive to all further traffic. No authentication, special headers, or large payload is required. Proxies such as NGINX and HAProxy legitimately forward trailer-bearing requests, so servers behind such proxies may be affected without any malicious client involvement. This issue affects bandit: from 1.6.1 before 1.11.1.
References
-
https://github.com/mtrudel/bandit/security/advisories/GHSA-rf5q-vwxw-gmrf exploitrelatedvendor-advisory
Affected products
- <1.11.1
- <ae3520dfdbfab115c638f8c7f6f6b805db34e1ab
Matching in nixpkgs
pkgs.bandit
Security oriented static analyser for python code
pkgs.python312Packages.bandit
None
pkgs.python313Packages.bandit
Security oriented static analyser for python code
pkgs.python314Packages.bandit
Security oriented static analyser for python code
Package maintainers
-
@kamadorueda Kevin Amado <kamadorueda@gmail.com>