CVE-2017-1000115

Mercurial prior to version 4.3 is vulnerable to a missing symlink check that can malicious repositories to modify files outside the repository

Weakness

The product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource.

Affected Software

Potential Mitigations

• Follow the principle of least privilege when assigning access rights to entities in a software system.
• Denying access to a file can prevent an attacker from replacing that file with a link to a sensitive file. Ensure good compartmentalization in the system to provide protected areas that can be trusted.

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/132.html
• https://cwe.mitre.org/data/definitions/17.html
• https://cwe.mitre.org/data/definitions/35.html
• https://cwe.mitre.org/data/definitions/76.html

References

• http://www.debian.org/security/2017/dsa-3963
• http://www.securityfocus.com/bid/100290
• https://access.redhat.com/errata/RHSA-2017:2489
• https://security.gentoo.org/glsa/201709-18
• https://www.mercurial-scm.org/wiki/WhatsNew#Mercurial_4.3_.2F_4.3.1_.282017-08-10.29