Vulnerabilities & CVEs SecurityWeek 3 weeks ago

WordPress Patches ‘Click2Shell’ Vulnerability

CN
CyberNew Threat Research Desk
• Original Reporting: SecurityWeek
CyberNew Threat Intel Assessment
Assessed Severity: CRITICAL
Impacted Surface
Enterprise Perimeter & Network Defense
Intelligence Sector
Vulnerabilities & CVEs

Analyst Takeaway

"WordPress last week released patches for 11 vulnerabilities, including a flaw that could potentially lead to remote code execution (RCE). Dubbed Click2Shell , the flaw does not have a CVE identifier yet. In its advisory, WordPress explains that it could be exploited via specially crafted URLs to automatically install and preview inactive themes. While this may sound relatively harmless, it is..."

Recommended Defense & Mitigation

  • Emergency Patching: Prioritize vendor patches and CVE mitigation across internet-facing assets immediately.
  • Perimeter Audit: Inspect perimeter firewall logs and hunt for unauthorized RCE indicators.
Curated & Verified by CyberNew Threat Intelligence Desk Standard Defense Framework (NIST / MITRE ATT&CK)
WordPress vulnerability exploited

WordPress last week released patches for 11 vulnerabilities, including a flaw that could potentially lead to remote code execution (RCE).

Dubbed Click2Shell, the flaw does not have a CVE identifier yet. In its advisory, WordPress explains that it could be exploited via specially crafted URLs to automatically install and preview inactive themes.

While this may sound relatively harmless, it is not: the inactive theme can be leveraged for RCE, according to pwn.ai, which was credited with finding and reporting the bug.

The issue, it explains, exists because a value in the WordPress theme-preview URL is interpreted differently by the themes API and by the JavaScript running in an administrator’s browser.

“The API reduces the value to an ordinary theme slug. The browser retains the original punctuation and places it inside a jQuery selector,” pwn.ai explains.

This allows an unauthenticated attacker to force the installation of an attacker-selected theme on the administrator’s site. The theme is fetched from the official WordPress.org catalog without the administrator’s knowledge or consent.

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While the theme is inactive and should not pose a threat, pwn.ai discovered that there are over 40 third-party themes on WordPress that could be abused for PHP code execution while inactive.

Written By Ionut Arghire

Source Verification & Original Intelligence

This threat report was reviewed by CyberNew analysts and cross-referenced with primary security disclosures from SecurityWeek.

Primary Advisory →