Arch Linux Security Advisory ASA-202102-38
=========================================
Severity: High
Date    : 2021-02-27
CVE-ID  : CVE-2021-20247
Package : isync
Type    : directory traversal
Remote  : Yes
Link    : https://security.archlinux.org/AVG-1598

Summary
======
The package isync before version 1.3.5-1 is vulnerable to directory
traversal.

Resolution
=========
Upgrade to 1.3.5-1.

# pacman -Syu "isync>=1.3.5-1"

The problem has been fixed upstream in version 1.3.5.

Workaround
=========
None.

Description
==========
A security issue was found in isync/mbsync before versions 1.3.5 and
1.4.1. Validations of the mailbox names returned by IMAP LIST/LSUB do
not occur, allowing a malicious or compromised server to use specially
crafted mailbox names containing '..' path components to access data
outside the designated mailbox on the opposite end of the
synchronization channel.

Impact
=====
A compromised server could traverse files on the system.

References
=========
https://www.openwall.com/lists/oss-security/2021/02/22/1
https://sourceforge.net/p/isync/isync/ci/fe5d59f8e3169944e57eb1c60155c9ebd4912d48/
https://security.archlinux.org/CVE-2021-20247