Executive brief
picklescan is a tool used to scan Python pickle files for malicious code. A vulnerability in versions before 1.0.1 allows an attacker to create empty files anywhere on the system's storage. While this cannot be used to steal data, it can be used to disrupt operations by creating 'lock' files that prevent the application from starting or functioning correctly.
Technical details
A deserialization vulnerability (CWE-502) exists in picklescan due to the unsafe processing of untrusted pickle data. By crafting a malicious payload that instantiates the 'logging.FileHandler' class, an attacker can bypass typical Remote Code Execution (RCE) blocklists. This exploit primitive allows for the creation of zero-byte files in arbitrary locations where the application has write permissions. While it does not allow for overwriting existing data, it can be used for filesystem pollution or to trigger a Denial of Service (DoS) by creating specific lock files that alter application logic. The issue is fixed in version 1.0.1.
Affected products
- mmaitre314 picklescan < 1.0.1
Timeline
- 2026-02-02: advisory: GitHub Security Advisory published
- 2026-06-20: disclosed: CVE-2026-56304 published to NVD