Requests has Insecure Temp File Reuse in its extract_zipped_paths() utility function

Vulnerability

Overview

The function requests.utils.extract_zipped_paths() in the popular Requests HTTP library (prior to version 2.33.0) extracts files from zip archives into the system's temporary directory using a predictable filename [1]. If a file with that name already exists at the extraction path, the function reuses it without any validation [4]. This design flaw allows a local attacker who has write access to the temporary directory to pre-create a malicious file under that predictable name. When an application then calls extract_zipped_paths(), the attacker's file is loaded in place of the legitimate archive content [1][4].

Exploitation

Prerequisites

Exploitation is limited to local attackers who already possess write access to the system's temporary directory [1]. Importantly, standard usage of the Requests library—such as normal requests.get() or requests.post() calls—does not invoke this utility function and is therefore unaffected [1][4]. Only applications that directly call extract_zipped_paths() are vulnerable [1][2][4]. No network-level privilege escalation is involved; the attack vector is purely local [1].

Impact

A successful attacker can substitute a malicious file (e.g., a Python module or configuration file) for a legitimate one extracted from a zip archive [1][4]. Depending on how the extracted file is subsequently used by the calling application, this could lead to arbitrary code execution, privilege escalation, or other integrity violations. The severity is reflected by CVSS 4.0 scoring (not detailed in the provided references) and the advisory's assessment of the bug as a security issue [1][3].

Mitigation

Requests version 2.33.0, released on 2026-03-25, remediates the vulnerability by extracting zip contents to a non-deterministic location, making it impossible for an attacker to predict the output path [1][3]. Developers who cannot immediately upgrade should set the TMPDIR environment variable to a directory with restricted write permissions, thereby denying local attackers the ability to plant files in the temp space [1][4]. No workaround exists for applications that must use the affected function without upgrading [1].