CVE-2018-20148

Exp

In WordPress before 4.9.9 and 5.x before 5.0.1, contributors could conduct PHP object injection attacks via crafted metadata in a wp.getMediaItem XMLRPC call. This is caused by mishandling of serialized data at phar:// URLs in the wp_get_attachment_thumb_file function in wp-includes/post.php.

Published: 2018-12-14 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2018-20148 is rated High Exploit Risk (83.5/100): CVSS Critical severity, with high exploitation likelihood (EPSS 54.86%, 98th percentile). Core evidence: 1 public exploit reference(s) are indexed (Exploit-DB). Mandatory action: Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2018-20148

EDB-ID Source Kind Published Link
nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2018-20148

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-03-04 61.70% 54.86% -6.84%
2 2026-03-01 54.86% 61.70% +6.84%
3 2026-02-04 54.86%

Full EPSS history (47 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2018-20148

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.8 3.0 CRITICAL
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
3.9 5.9 [email protected]
7.5 2.0 HIGH
AV:N/AC:L/Au:N/C:P/I:P/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
10.0 6.4 [email protected]

Weakness enumeration for CVE-2018-20148

OS Trackers for CVE-2018-20148

vendor priority summary link
debian not yet assigned CVE-2018-20148 not yet assigned priority: Debian including 1 source packages (wordpress), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2018-20148
ubuntu medium CVE-2018-20148 medium priority: Ubuntu including 1 source packages (wordpress), 19 status rows across 19 suites (bionic, cosmic, disco, eoan, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): not-affected 14, needed 2, DNE 1, ignored 1, released 1. https://ubuntu.com/security/CVE-2018-20148

Affected software / configurations for CVE-2018-20148

Vendor Product Version Raw CPE
wordpress wordpress < 4.9.9 cpe:2.3:a:wordpress:wordpress:*:*:*:*:*:*:*:*
wordpress wordpress >= 5.0, < 5.0.1 cpe:2.3:a:wordpress:wordpress:*:*:*:*:*:*:*:*
debian debian_linux 8.0 cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*
debian debian_linux 9.0 cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*

References for CVE-2018-20148

URL Tags
http://www.securityfocus.com/bid/106220 Third Party Advisory VDB Entry
https://blog.secarma.co.uk/labs/near-phar-dangerous-unserialization-wherever-you-are Exploit Third Party Advisory
https://codex.wordpress.org/Version_4.9.9 Product Vendor Advisory
https://lists.debian.org/debian-lts-announce/2019/02/msg00019.html Mailing List Third Party Advisory
https://wordpress.org/news/2018/12/wordpress-5-0-1-security-release/ Release Notes Vendor Advisory
https://wordpress.org/support/wordpress-version/version-5-0-1/ Release Notes Vendor Advisory
https://wpvulndb.com/vulnerabilities/9171 Vendor Advisory
https://www.debian.org/security/2019/dsa-4401 Third Party Advisory
https://www.zdnet.com/article/wordpress-plugs-bug-that-led-to-google-indexing-some-user-passwords/ Press/Media Coverage Third Party Advisory
https://www.zdnet.com/article/wordpress-vulnerability-affects-a-third-of-most-popular-websites-online/ Press/Media Coverage Third Party Advisory
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