CVE-2021-28153

An issue was discovered in GNOME GLib before 2.66.8. When g_file_replace() is used with G_FILE_CREATE_REPLACE_DESTINATION to replace a path that is a dangling symlink, it incorrectly also creates the target of the symlink as an empty file, which could conceivably have security relevance if the symlink is attacker-controlled. (If the path is a symlink to a file that already exists, then the contents of that file correctly remain unchanged.)

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

• https://gitlab.gnome.org/GNOME/glib/-/issues/2325
• https://lists.debian.org/debian-lts-announce/2022/06/msg00006.html
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/6RXTD5HCP2K4AAUSWWZTBKQNHRCTAEOF/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ICUTQPHZNZWX2DZR46QFLQZRHVMHIILJ/
• https://security.gentoo.org/glsa/202107-13
• https://security.netapp.com/advisory/ntap-20210416-0003/