trailofbits fickling up to 0.1.5 Pickle incomplete blacklist

Summaryinfo

A vulnerability was found in trailofbits fickling up to 0.1.5. It has been declared as critical. The impacted element is an unknown function of the component Pickle Handler. The manipulation results in incomplete blacklist. This vulnerability is reported as CVE-2025-67747. The attack can be launched remotely. No exploit exists. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in trailofbits fickling up to 0.1.5. It has been classified as critical. Affected is some unknown processing of the component Pickle Handler. The manipulation with an unknown input leads to a incomplete blacklist vulnerability. CWE is classifying the issue as CWE-184. The product implements a protection mechanism that relies on a list of inputs (or properties of inputs) that are not allowed by policy or otherwise require other action to neutralize before additional processing takes place, but the list is incomplete, leading to resultant weaknesses. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

Fickling is a Python pickling decompiler and static analyzer. Versions prior to 0.1.6 are missing `marshal` and `types` from the block list of unsafe module imports. Fickling started blocking both modules to address this issue. This allows an attacker to craft a malicious pickle file that can bypass fickling since it misses detections for `types.FunctionType` and `marshal.loads`. A user who deserializes such a file, believing it to be safe, would inadvertently execute arbitrary code on their system. This impacts any user or system that uses Fickling to vet pickle files for security issues. The issue was fixed in version 0.1.6.

The advisory is shared for download at github.com. This vulnerability is traded as CVE-2025-67747 since 12/11/2025. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. Successful exploitation requires user interaction by the victim. There are neither technical details nor an exploit publicly available. The MITRE ATT&CK project declares the attack technique as T1562.006.

Upgrading to version 0.1.6 eliminates this vulnerability. The upgrade is hosted for download at github.com. Applying the patch 4e34561301bda1450268d1d7b0b2b151de33b913 is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at CNNVD (CNNVD-202512-3124). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Type

• Application Server Software

Vendor

• trailofbits

Name

• fickling

Version

• 0.1.0
• 0.1.1
• 0.1.2
• 0.1.3
• 0.1.4
• 0.1.5

License

• open-source

Website

• Product: https://github.com/trailofbits/fickling/

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

VulDB is the best source for vulnerability data and more expert information about this specific topic.

Discussion