How severe is CVE-2018-19518?

CVE-2018-19518 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with high attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2018-19518 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 95% (100th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2018-19518?

CVE-2018-19518 primarily affects Php. In total, 7 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2018-19518?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2018-19518 published?

CVE-2018-19518 was published on 2018-11-25 and last updated on 2026-06-17.

CVE-2018-19518

CVE-2018-19518 is a high-severity vulnerability in Php with a CVSS 3.x base score of 7.5. Its EPSS exploit-prediction score of 95% places it in the 100th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-88.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 8.5
EPSS exploit prediction: 95% (100th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-88
Affected product: Php
Published: 2018-11-25
Last modified: 2026-06-17

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OS commands if the IMAP server name is untrusted input (e.g., entered by a user of a web application) and if rsh has been replaced by a program with different argument semantics.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.

Frequently asked questions

What is CVE-2018-19518?: 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.
How severe is CVE-2018-19518?: CVE-2018-19518 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with high attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2018-19518 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 95% (100th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2018-19518?: CVE-2018-19518 primarily affects Php. In total, 7 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2018-19518?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2018-19518 published?: CVE-2018-19518 was published on 2018-11-25 and last updated on 2026-06-17.

References

Affected products (7)

cpe:2.3:a:php:php:*:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
cpe:2.3:a:uw-imap_project:uw-imap:2007f:*:*:*:*:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:esm:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:19.04:*:*:*:*:*:*:*

More vulnerabilities in Php

CVE-2015-0235 — Critical (CVSS 10.0): Heap-based buffer overflow in the __nss_hostname_digits_dots function in glibc 2.2, and other 2.x versions before 2.18,…
CVE-2012-2688 — Critical (CVSS 10.0): Unspecified vulnerability in the _php_stream_scandir function in the stream implementation in PHP before 5.3.15 and…
CVE-2012-2376 — Critical (CVSS 10.0): Buffer overflow in the com_print_typeinfo function in PHP 5.4.3 and earlier on Windows allows remote attackers to…
CVE-2011-3268 — Critical (CVSS 10.0): Buffer overflow in the crypt function in PHP before 5.3.7 allows context-dependent attackers to have an unspecified…
CVE-2009-4143 — Critical (CVSS 10.0): PHP before 5.2.12 does not properly handle session data, which has unspecified impact and attack vectors related to (1)…
CVE-2008-5557 — Critical (CVSS 10.0): Heap-based buffer overflow in ext/mbstring/libmbfl/filters/mbfilter_htmlent.c in the mbstring extension in PHP 4.3.0…

All CVEs affecting Php →

Other CWE-88 (Argument Injection) vulnerabilities

CVE-2026-57572 — Critical (CVSS 10.0): Crawl4AI is an open-source LLM-friendly web crawler and scraper. Prior to 0.9.0, the Docker API server accepted…
CVE-2026-40281 — Critical (CVSS 10.0): Gotenberg is a Docker-powered stateless API for PDF files. In versions 8.30.1 and earlier, the metadata write endpoint…
CVE-2023-6269 — Critical (CVSS 10.0): An argument injection vulnerability has been identified in the administrative web interface of the Atos Unify…
CVE-2007-0882 — Critical (CVSS 10.0): Argument injection vulnerability in the telnet daemon (in.telnetd) in Solaris 10 and 11 (SunOS 5.10 and 5.11)…
CVE-2004-0480 — Critical (CVSS 10.0): Argument injection vulnerability in IBM Lotus Notes 6.0.3 and 6.5 allows remote attackers to execute arbitrary code via…
CVE-1999-0113 — Critical (CVSS 10.0): Some implementations of rlogin allow root access if given a -froot parameter.

Browse all CWE-88 (Argument Injection) vulnerabilities →

Threat intelligence

Threat-intel indicators referencing this CVE:

182.93.50.90 (ipv4-addr)
117.247.23.131 (ipv4-addr)
103.38.182.49 (ipv4-addr)
103.165.139.145 (ipv4-addr)
103.158.40.65 (ipv4-addr)
221.182.185.190 (ipv4-addr)
61.143.227.17 (ipv4-addr)
218.29.231.106 (ipv4-addr)