Unauthenticated AJAX Endpoint Allows Arbitrary Function Execution

The Streamit WordPress theme through 4.5.0 does not perform any authorization or nonce verification on one of its unauthenticated AJAX routes, which invokes an attacker-supplied PHP function with an attacker-supplied argument array, allowing unauthenticated attackers to call arbitrary functions (for example to create an administrator account), leading to privilege escalation and remote code execution.

Casky was already ahead

This CVE exploits attack patterns that Casky's 322matched skills already investigate — long before this vulnerability was disclosed. Claude's reasoning model maps these techniques to MITRE ATT&CK, so practitioners who ran these skills have already seen the threat behaviour in their findings.

Analysis

The Streamit WordPress theme contains a critical vulnerability in its AJAX handling that completely bypasses authentication and authorization controls. An unauthenticated attacker can invoke arbitrary PHP functions with attacker-controlled arguments through an exposed AJAX route, enabling them to perform privileged actions such as creating administrator accounts. This affects all installations of Streamit through version 4.5.0, making it a severe threat to any WordPress site using this popular theme. The vulnerability combines missing authorization checks with unsafe function invocation, creating a direct path to privilege escalation and remote code execution.

Casky's 322 matching skills leverage Claude's extended reasoning to detect the attack patterns underlying this vulnerability across MITRE ATT&CK's Initial Access (TA0001) and Privilege Escalation (TA0043) techniques. Practitioners using Casky would identify suspicious patterns including: unauthenticated AJAX requests to unexpected endpoints, function calls with suspicious argument arrays, PHP function invocation patterns (particularly those creating users or executing code), and account creation events originating from non-admin API calls. The platform's deep mapping to CWE-94 (Improper Control of Generation of Code) enables detection of function call chains that circumvent authorization, while Claude's reasoning capability helps correlate seemingly disparate events—like AJAX requests followed by new admin accounts—into a cohesive attack narrative that reveals exploitation attempts before they succeed.

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Casky Risk Score

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EPSS Probability

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Shodan Exposure

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GreyNoise Signal

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Composite risk scoring from EPSS, CISA KEV, Shodan, and GreyNoise — 21 security APIs correlated into a single Casky Risk Score. Coming in Casky Pro. Join early access →

322 Casky skills cover this attack pattern

These skills use Claude AI's reasoning model to surface findings in the same attack categories as CVE-2026-13423.

Abuse of Public-Facing API: Mobile API Abuse

mobile security · low

Run

abusing-dpapi-for-credential-access

red teaming · high

Run

abusing-shadow-credentials-for-privesc

red teaming · high

Run

MITRE ATT&CK Techniques

TA0001 TA0043

Investigate the attack patterns behind CVE-2026-13423

Casky has 322 skills that investigate the attack patterns behind CVE-2026-13423. Run one and get CVSS-scored findings in 3 minutes.

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