Описание
Aqua's archive extraction follows attacker-planted symlinks, allowing writes outside the install directory
Summary
aquaproj/aqua extracts downloaded tool archives through pkg/unarchive/archives.go using github.com/mholt/archives. The archive handler creates symlink entries with os.Symlink(f.LinkTarget, dstPath) without validating that the symlink target resolves inside the extraction destination. A subsequent regular-file archive entry with the same path is opened with OpenFile(dstPath, O_CREATE|O_WRONLY), which follows the attacker-planted symlink.
A malicious or compromised aqua package / release asset can therefore write attacker-controlled bytes outside aqua's extraction directory, with the privileges of the user running aqua.
Details
Affected file: pkg/unarchive/archives.go
Affected function: (*handler).HandleFile
The vulnerable logic is the combination of:
for symlink entries, followed by:
for a later regular file entry at the same archive path. The symlink target is not jailed to the extraction destination, and the later file open follows the symlink.
The attached PoC uses a two-entry tar.gz archive:
- symlink
pwn -> <outside target>; - regular file
pwncontaining attacker-controlled bytes.
The same mholt/archives extraction flow is used for the vulnerable handler and for a negative-control handler using a destination-root jail.
PoC
Attachment: submission_aqua_archive_symlink_traversal_v2_final.zip
Run:
Expected vulnerable result:
Expected safe-control result:
Impact
An attacker who controls an archive that aqua installs can write attacker-controlled content to paths outside the extraction destination, limited by the filesystem permissions of the user running aqua. This can lead to user-level code execution if the overwritten path is later executed or interpreted, for example a shell startup file, a tool configuration file, or a writable PATH entry.
This report does not claim privilege escalation beyond the aqua process privileges.
Пакеты
github.com/aquaproj/aqua/v2
< 2.60.1
2.60.1
Связанные уязвимости
aqua is a declarative command-line version manager written in Go. Prior to 2.60.1, pkg/unarchive/archives.go in the handler.HandleFile method calls os.Symlink with archives.FileInfo.LinkTarget without verifying that the target remains under the extraction destination. A later regular-file entry at the same archive path is opened with OpenFile using O_CREATE and O_WRONLY, which follows the attacker-planted symlink. A malicious or compromised package archive can therefore write attacker-controlled bytes outside aqua's extraction directory with the privileges of the user running aqua, potentially overwriting shell startup files, tool configuration, or writable executable paths. This issue is fixed in version 2.60.1.