#VU59879 Input validation error in Cyrus IMAP Server - CVE-2021-33582

Vulnerability identifier: #VU59879

Vulnerability risk: Medium

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

CVE-ID: CVE-2021-33582

CWE-ID: CWE-20

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Cyrus IMAP Server
Server applications / Other server solutions

Vendor: Carnegie Mellon University

Description

The vulnerability allows remote attackers to perform a denial of service (DoS) attack.

The vulnerability exists due to insufficient validation of user-supplied input that is mishandled during hash-table interaction. A remote attacker can cause a denial of service (multiple-minute daemon hang) via input that is mishandled during hash-table interaction. Because there are many insertions into a single bucket, strcmp becomes slow.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Cyrus IMAP Server: 3.0.0 - 3.4.1

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External links
https://www.cyrusimap.org/imap/download/release-notes/index.html
https://github.com/cyrusimap/cyrus-imapd/commits/master
https://cyrus.topicbox.com/groups/announce/T3dde0a2352462975-M1386fc44adf967e072f8df13/cyrus-imap-3-4-2-3-2-8-and-3-0-16-released
https://github.com/cyrusimap/cyrus-imapd/security/advisories

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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.