CVE-2014-4663

TimThumb <= 2.8.13 - Remote Code Execution

2014-07-04 00:00
Pichaya Morimoto

Strategic Overview

Status
Unpatched
Affected Plugin
User Avatar
Affected Version
<= 1.4.12
CVSS
9.8Critical
Weakness type
CWE-94 · Improper Control of Generation of Code ('Code Injection')
CVE
CVE-2014-4663
View all User Avatar vulnerabilities

At a glance

CVE-2014-4663 is a critical-severity Improper Control of Generation of Code ('Code Injection') vulnerability in the User Avatar WordPress plugin, affecting versions <= 1.4.12. It carries a CVSS score of 9.8 (reachable over the network; low attack complexity; high confidentiality, integrity, availability impact). Exploitation requires no authentication. No fixed release has been reported yet; treat installations running this software as exposed. Disclosed July 2014, reported by Pichaya Morimoto.

Vulnerability Overview

TimThumb 2.8.13 and WordThumb 1.07, when Webshot (aka Webshots) is enabled, allows remote attackers to execute arbitrary commands via shell metacharacters in the src parameter. Note: this is not a WordPress plugin or theme, but may be used by WordPress plugins and themes. Make sure to check for the presence of the timthumb.php file when determining if your installation is vulnerable.

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, and no interaction from a victim user. 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 User Avatar <= 1.4.12 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. No fixed build of this plugin is recorded for User Avatar yet, so installs running <= 1.4.12 stay exposed until the vendor ships one.

Remediation

No known patch available. Please review the vulnerability's details in depth and employ mitigations based on your organization's risk tolerance. It may be best to uninstall the affected software and find a replacement.

How does WordSec protect against this?

The attempt arrives as an ordinary request to User Avatar: 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. No patched version is recorded yet, which is the case where a filtering layer matters most, because there is nothing to update to.

  • Firewall
  • Scanner
  • Alerts

External References

Related records

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