Source: cve@mitre.org
Multiple cross-site request forgery (CSRF) vulnerabilities in the SimpleFlickr plugin 3.0.3 and earlier for WordPress allow remote attackers to hijack the authentication of administrators for requests that conduct cross-site scripting (XSS) attacks via the (1) simpleflickr_width, (2) simpleflickr_bgcolor, or (3) simpleflickr_xmldatapath parameter in the simpleFlickr.php page to wp-admin/options-general.php.
SimpleFlickr plugin versions 3.0.3 and earlier for WordPress are vulnerable to Cross-Site Request Forgery (CSRF) attacks, enabling attackers to hijack administrator sessions. This allows attackers to inject malicious JavaScript code (XSS) into the plugin's configuration, potentially leading to complete site compromise. Successful exploitation can result in remote code execution, data theft, and website defacement.
Step 1: Craft Malicious Payload: The attacker crafts a malicious HTML form or JavaScript code containing the payload. This payload targets the wp-admin/options-general.php page of the WordPress site. The payload includes the vulnerable parameters (simpleflickr_width, simpleflickr_bgcolor, or simpleflickr_xmldatapath) with the attacker's injected JavaScript code.
Step 2: Social Engineering (or other means): The attacker delivers the payload to a logged-in WordPress administrator. This can be achieved through various methods, such as phishing emails, malicious advertisements, or compromised websites. The goal is to trick the administrator into executing the malicious code.
Step 3: Payload Execution: When the administrator visits the attacker's crafted page or interacts with the malicious element, the payload is executed. The malicious JavaScript code is sent to the vulnerable endpoint.
Step 4: Configuration Update: The vulnerable plugin processes the request. Because of the lack of CSRF protection, the plugin accepts the attacker's malicious input and updates the plugin's settings with the injected JavaScript.
Step 5: XSS Execution: When the plugin processes the modified settings, the injected JavaScript code is executed in the administrator's browser. This allows the attacker to perform actions on behalf of the administrator, such as creating new administrator accounts, stealing sensitive data (cookies, session tokens), or defacing the website.
The vulnerability stems from a lack of CSRF protection in the SimpleFlickr plugin's configuration update functionality. Specifically, the plugin fails to validate the origin of requests when updating settings via the wp-admin/options-general.php page. This allows an attacker to craft a malicious HTML form or JavaScript code that, when executed by a logged-in administrator, modifies the plugin's settings. The attacker leverages this to inject malicious JavaScript into the plugin's configuration parameters (simpleflickr_width, simpleflickr_bgcolor, simpleflickr_xmldatapath). When the plugin processes these settings, the injected JavaScript executes in the context of the administrator's browser, leading to XSS. The root cause is the absence of a nonce or other CSRF protection mechanism to verify the authenticity of configuration update requests.
This vulnerability could be exploited by various threat actors, including those seeking to deface websites, steal data, or establish a foothold for further attacks. While no specific APTs are directly linked, the ease of exploitation makes it attractive to a wide range of attackers. Not listed on CISA KEV.
Monitor web server logs for suspicious POST requests to wp-admin/options-general.php with parameters related to the SimpleFlickr plugin (e.g., simpleflickr_width, simpleflickr_bgcolor, simpleflickr_xmldatapath).
Analyze HTTP request headers for missing or invalid CSRF tokens (e.g., X-CSRF-Token).
Implement a Web Application Firewall (WAF) to detect and block malicious requests, including those containing XSS payloads.
Monitor for unusual JavaScript activity or redirects within the WordPress admin interface.
Review plugin configuration settings for unexpected or malicious JavaScript code.
Update the SimpleFlickr plugin to version 3.0.4 or later. This version likely includes the necessary CSRF protection.
Implement a Web Application Firewall (WAF) to filter malicious requests.
Regularly scan the website for vulnerabilities using a vulnerability scanner.
Enforce strong password policies and multi-factor authentication (MFA) for all administrator accounts.
Educate administrators about phishing and social engineering attacks.
Review and sanitize all user-supplied input to prevent XSS attacks.