#VU23774 Input validation error in Cyrus IMAP Server - CVE-2019-19783

Vulnerability identifier: #VU23774

Vulnerability risk: Medium

CVSSv4.0: 1.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2019-19783

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 a remote user to escalate privileges within the application.

The vulnerability exists due to insufficient validation of user-supplied input in autosieve_createfolder() function in imap/lmtp_sieve.c. A remote email user can create any mailbox with administrative privileges.

Successful exploitation of the vulnerability requires that the sieve script uploading is allowed (3.x) or certain non-default sieve options are enabled (2.x).

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Cyrus IMAP Server: 2.5.0 - 3.1.8

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External links
https://www.cyrusimap.org/imap/download/release-notes/2.5/x/2.5.15.html
https://www.cyrusimap.org/imap/download/release-notes/3.0/x/3.0.13.html

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.

Is there known malware, which exploits this vulnerability?

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