CVE-2018-19518
HighExploitedPublic exploitUniversity 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,…
Published Nov 25, 2018 · Updated Aug 7, 2026 · Also known as DEBIAN-CVE-2018-19518, DEBIAN-CVE-2018-19935, DEBIAN-CVE-2018-20783, DLA-1608-1, DLA-1700-1, DLA-2866-1, SUSE-SU-2018:3986-1, SUSE-SU-2018:3988-1, SUSE-SU-2018:3995-1, UBUNTU-CVE-2018-19518, USN-4160-1
Key Facts
Patch immediately- CVE-2018-19518 is a high-severity vulnerability (CVSS 7.5 v3.1) affecting PHP, Uw-Imap (Uw-Imap Project), Ubuntu Linux (Canonical) and 22 more products.
- It is exploited in the wild, listed in Industry KEV feed since Feb 14, 2023 and is known to be used in ransomware campaigns. Public exploit code is available.
- EPSS estimates a 96% probability of exploitation in the next 30 days.
- Fixed versions are available, including apache2-mod_php5 5.5.14-109.1, apache2-mod_php5 5.5.14-109.45.2, apache2-mod_php53 5.3.17-112.45.1.
- Brandefense priority: patch immediately, because it is listed as exploited in the wild.
CVSS v3.1
7.5
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS (30-day exploit likelihood)
96%
Higher than 99.8% of all scored CVEs
Exploited in the wild
Yes
1 catalog listing, used by ransomware
Public exploit code
Available
Proof-of-concept or weaponized module
Get the full CVE-2018-19518 brief as a PDF
Every affected product and fixed release, exploitation status and a first 24 hours response checklist, emailed within minutes.
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OS commands if the IMAP server name is untrusted input (e.g., entered by a user of a web application) and if rsh has been replaced by a program with different argument semantics.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.
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| Industry KEV feed | Feb 14, 2023 | n/a | Known |
Required action: Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.
Affected Products
480 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| PHPPHP | See advisory | 5.6.38 |
| Uw-ImapUw-Imap Project | 2007f | 8:2007f~dfsg-6 |
| Ubuntu LinuxCanonical | 16.04, 18.04, 19.04 | n/a |
| Debian LinuxDebian | 8.0, 9.0 | n/a |
| php7alpine | See advisory | 7.1.29-r0 |
Patched Releases
apache2-mod_php5
5.5.14-109.1, 5.5.14-109.45.2
apache2-mod_php53
5.3.17-112.45.1
apache2-mod_php7
7.0.7-50.56.2, 7.0.7-52.1
PHP
<=5.6.38
php-imap
5.4.6-0ubuntu5.1
php5
5.5.14-109.1, 5.5.14-109.45.2, 5.6.39+dfsg-0+deb8u1
php5-bcmath
5.5.14-109.1, 5.5.14-109.45.2
php5-bz2
5.5.14-109.1, 5.5.14-109.45.2
php5-calendar
5.5.14-109.1, 5.5.14-109.45.2
php5-ctype
5.5.14-109.1, 5.5.14-109.45.2
php5-curl
5.5.14-109.1, 5.5.14-109.45.2
php5-dba
5.5.14-109.1, 5.5.14-109.45.2
php5-devel
5.5.14-109.1, 5.5.14-109.45.2
php5-dom
5.5.14-109.1, 5.5.14-109.45.2
php5-enchant
5.5.14-109.1, 5.5.14-109.45.2
php5-exif
5.5.14-109.1, 5.5.14-109.45.2
php5-fastcgi
5.5.14-109.1, 5.5.14-109.45.2
php5-fileinfo
5.5.14-109.1, 5.5.14-109.45.2
php5-firebird
5.5.14-109.1
php5-fpm
5.5.14-109.1, 5.5.14-109.45.2
php5-ftp
5.5.14-109.1, 5.5.14-109.45.2
php5-gd
5.5.14-109.1, 5.5.14-109.45.2
php5-gettext
5.5.14-109.1, 5.5.14-109.45.2
php5-gmp
5.5.14-109.1, 5.5.14-109.45.2
php5-iconv
5.5.14-109.1, 5.5.14-109.45.2
Timeline
Publicly disclosed
Nov 25, 2018
Added to Industry KEV feed
Feb 14, 2023
Last updated
Aug 7, 2026
Weakness Type
- CWE-78 Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
- CWE-88 Improper Neutralization of Argument Delimiters in a Command ('Argument Injection')
References
- advisoryhttps://bugs.debian.org/913775
- advisoryhttps://bugs.debian.org/913835
- advisoryhttps://bugs.debian.org/913836
- advisoryhttps://bugs.php.net/bug.php?id=77160
- advisoryhttps://bugzilla.suse.com/1117107
FAQ
Common Questions.
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 exe…
Affected: PHP; Uw-Imap (Uw-Imap Project) versions 2007f; Ubuntu Linux (Canonical) versions 16.04, 18.04, 19.04, among others. The full list is in the CVE brief.
It is exploited in the wild, listed in Industry KEV feed since Feb 14, 2023 and is known to be used in ransomware campaigns.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
Public exploit code is available.
Fixed versions are available, including apache2-mod_php5 5.5.14-109.1, apache2-mod_php5 5.5.14-109.45.2, apache2-mod_php53 5.3.17-112.45.1.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
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