CVE-2026-13723
6.5
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L
Exploitability: 3.9 / Impact: 2.5
Source: 134c704f-9b21-4f2e-91b3-4a467353bcc0 (Secondary)
Description
A vulnerability in the `zipx.Unzip` extraction routine of Develar's app-builder allows an attacker to overwrite arbitrary files on macOS APFS by exploiting a Unicode Normalization Collision combined with symlink following behavior. APFS treats certain Unicode equivalent filenames as identical (e.g., ß ↔ ss), while app builder performs no canonical normalization before validating or writing paths. As a result, a crafted ZIP archive containing:
• a symlink entry named ss pointing to a target file, and
• a regular file named ß containing attacker controlled data,
will cause the second write to follow the symlink and overwrite the target file.
Related CWEs
CWE-22
Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.
CWE-59
Improper Link Resolution Before File Access ('Link Following')
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.
References (4)
Source: cret@cert.org
Source: cret@cert.org
Source: cret@cert.org
Source: af854a3a-2127-422b-91ae-364da2661108
Timeline
No history available yet.