CVE-2016-20010

EWWW Image Optimizer <= 2.8.4 - Remote Code Execution

2016-06-08 00:00
Sean Murphy

Strategic Overview

Status
Patched in 2.8.5
Affected Plugin
EWWW Image Optimizer
Affected Version
<= 2.8.4
CVSS
9.6Critical
Weakness type
CWE-94 · Improper Control of Generation of Code ('Code Injection')
CVE
CVE-2016-20010
View all EWWW Image Optimizer vulnerabilities

At a glance

CVE-2016-20010 is a critical-severity Improper Control of Generation of Code ('Code Injection') vulnerability in the EWWW Image Optimizer WordPress plugin, affecting versions <= 2.8.4. It carries a CVSS score of 9.6 (reachable over the network; low attack complexity; high confidentiality, integrity, availability impact). Exploitation requires no authentication. The issue is fixed in version 2.8.5; sites on affected versions should update now. Disclosed June 2016, reported by Sean Murphy.

Vulnerability Overview

EWWW Image Optimizer before 2.8.5 allows remote command execution because it relies on a protection mechanism involving boolval, which is unavailable before PHP 5.5. Version 2.8.4 provides a partial fix.

Technical Analysis

The vector marks this flaw as remotely reachable over the network, with low attack complexity — no special timing or configuration is needed, and no privileges on the target site. A successful exploit has high impact on confidentiality, integrity, availability — full site compromise territory.

CWE-94: Improper Control of Generation of Code ('Code Injection')

Reaching this weakness in EWWW Image Optimizer <= 2.8.4 takes a caller who can reach the endpoint. Code injection means input from a request reaches a language construct that evaluates code, so the attacker's text is executed rather than treated as data.

The injected code runs with the web server's privileges, giving the attacker the same access to the database and filesystem as WordPress itself. For EWWW Image Optimizer the fix is 2.8.5: builds <= 2.8.4 are affected, anything from 2.8.5 onward is not.

Remediation

Update to version 2.8.5, or a newer patched version

How does WordSec protect against this?

The attempt arrives as an ordinary request to EWWW Image Optimizer: WordSec's web application firewall inspects request payloads before WordPress loads them. Classes like this one can leave something behind, so the staged malware scanner is the second half: it looks for dropped files and modified code rather than for the request that created them. None of that substitutes for the fix: EWWW Image Optimizer 2.8.5 closes this, and updating the plugin is the step that ends it.

  • Firewall
  • Scanner
  • Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2016-20010https://www.wordfence.com/threat-intel/vulnerabilities/id/7ffac29d-d1cc-4d5d-aff8-0cb639a1e3d7https://nvd.nist.gov/vuln/detail/CVE-2016-20010

Related records

Vulnerability data © Defiant, Inc., provided under the Wordfence Intelligence T&C