RestrictedPython up to 5.3/6.1 Format injection

Summaryinfo

A vulnerability has been found in RestrictedPython up to 5.3/6.1 and classified as problematic. Impacted is an unknown function of the component Format Handler. Performing a manipulation results in injection. This vulnerability was named CVE-2023-41039. The attack may be initiated remotely. There is no available exploit. The affected component should be upgraded.

Detailsinfo

A vulnerability was found in RestrictedPython up to 5.3/6.1 (Programming Language Software). It has been classified as problematic. This affects an unknown part of the component Format Handler. The manipulation with an unknown input leads to a injection vulnerability. CWE is classifying the issue as CWE-74. The product constructs all or part of a command, data structure, or record using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify how it is parsed or interpreted when it is sent to a downstream component. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

RestrictedPython is a restricted execution environment for Python to run untrusted code. Python's "format" functionality allows someone controlling the format string to "read" all objects accessible through recursive attribute lookup and subscription from objects he can access. This can lead to critical information disclosure. With `RestrictedPython`, the format functionality is available via the `format` and `format_map` methods of `str` (and `unicode`) (accessed either via the class or its instances) and via `string.Formatter`. All known versions of `RestrictedPython` are vulnerable. This issue has been addressed in commit `4134aedcff1` which has been included in the 5.4 and 6.2 releases. Users are advised to upgrade. There are no known workarounds for this vulnerability.

The weakness was presented 08/30/2023 as GHSA-xjw2-6jm9-rf67. The advisory is shared at github.com. This vulnerability is uniquely identified as CVE-2023-41039 since 08/22/2023. It demands that the victim is doing some kind of user interaction. Neither technical details nor an exploit are publicly available. MITRE ATT&CK project uses the attack technique T1055 for this issue.

The vulnerability scanner Nessus provides a plugin with the ID 232986 (Ubuntu 20.04 LTS / 22.04 LTS / 24.04 LTS / 24.10 : RestrictedPython vulnerabilities (USN-7355-1)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 5.4 or 6.2 eliminates this vulnerability. Applying the patch 4134aedcff17c977da7717693ed89ce56d54c120 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 Tenable (232986). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Type

• Programming Language Software

Name

• RestrictedPython

Version

• 5.0
• 5.1
• 5.2
• 5.3
• 6.0
• 6.1

License

• open-source

CPE 2.3info

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• 🔍
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CPE 2.2info

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Entryinfo

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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