What’s Vulnerable › Vulnerabilities

CVE-2018-19518

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 96.1% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2018-11-25 · updated 2026-06-17
• Weakness: CWE-88

Description

University of Washington IMAP Toolkit 2007f on UNIX, as used in imap_open() in PHP and other products, launches an rsh command (by means of the imap_rimap function in c-client/imap4r1.c and the tcp_aopen function in osdep/unix/tcp_unix.c) without preventing argument injection, which might allow remote attackers to execute arbitrary OS commands if the IMAP server name is untrusted input (e.g., entered by a user of a web application) and if rsh has been replaced by a program with different argument semantics. For example, if rsh is a link to ssh (as seen on Debian and Ubuntu systems), then the attack can use an IMAP server name containing a "-oProxyCommand" argument.

Affected products

• Canonical Ubuntu Linux: 16.04, 18.04, 19.04
• Debian Linux: 8.0, 9.0
• PHP: from 5.6.0 through 5.6.38; from 7.0.0 through 7.0.32; from 7.1.0 through 7.1.24; from 7.2.0 through 7.2.12
• Uw-Imap Project Uw-Imap: 2007f

References

• http://www.securityfocus.com/bid/106018
• http://www.securitytracker.com/id/1042157
• https://antichat.com/threads/463395/#post-4254681
• https://bugs.debian.org/913775
• https://bugs.debian.org/913835
• https://bugs.debian.org/913836
• https://bugs.php.net/bug.php?id=76428
• https://bugs.php.net/bug.php?id=77153
• https://bugs.php.net/bug.php?id=77160
• https://git.php.net/?p=php-src.git%3Ba=commit%3Bh=e5bfea64c81ae34816479bb05d17cdffe45adddb
• https://github.com/Bo0oM/PHP_imap_open_exploit/blob/master/exploit.php
• https://lists.debian.org/debian-lts-announce/2018/12/msg00006.html

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