#VU50871 Path traversal in Isync: mailbox synchronizer - CVE-2021-20247

Vulnerability identifier: #VU50871

Vulnerability risk: Medium

CVSSv4.0: 6.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2021-20247

CWE-ID: CWE-22

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Isync: mailbox synchronizer
Other software / Other software solutions

Vendor: ossi

Description

The vulnerability allows a remote attacker to perform directory traversal attacks.

The vulnerability exists due to improper validation of mailbox names returned by IMAP LIST/LSUB in the mbsync command. A remote attacker can send a specially crafted HTTP request and read arbitrary files on the system.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Isync: mailbox synchronizer: 1.3.4 - 1.4.0

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External links
https://seclists.org/oss-sec/2021/q1/170

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.