CVE-2017-18561 in embed-comment-images Plugin
Summary
by MITRE
The embed-comment-images plugin before 0.6 for WordPress has XSS.
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Analysis
by VulDB Data Team • 11/28/2023
The CVE-2017-18561 vulnerability represents a cross-site scripting flaw in the embed-comment-images plugin for WordPress systems prior to version 0.6. This security weakness resides within the plugin's handling of user-provided comment data, specifically when processing embedded image content within comment sections. The vulnerability arises from insufficient input validation and output sanitization mechanisms that fail to properly escape or filter malicious script code submitted through comment fields. Attackers can exploit this flaw by injecting malicious javascript code into comment forms, which then executes in the context of other users' browsers when they view the affected comments. The vulnerability directly impacts the integrity and security of WordPress installations that utilize this plugin, potentially allowing attackers to hijack user sessions, steal sensitive information, or perform unauthorized actions on behalf of authenticated users.
The technical implementation of this vulnerability stems from improper handling of comment data within the plugin's image embedding functionality. When users submit comments containing embedded image URLs or image-related metadata, the plugin fails to adequately sanitize this input before rendering it on web pages. This creates an environment where malicious actors can craft specially formatted comments that include javascript payloads, typically leveraging techniques such as script tag injection or event handler manipulation. The flaw operates under CWE-79 which categorizes cross-site scripting vulnerabilities as weaknesses in input validation and output encoding. The vulnerability is particularly dangerous because it leverages the trust relationship between legitimate users and the WordPress platform, allowing attackers to execute code in the browsers of unsuspecting visitors who view affected comments.
The operational impact of CVE-2017-18561 extends beyond simple data theft or defacement, as it can enable more sophisticated attack vectors within the broader context of the ATT&CK framework. Specifically, this vulnerability aligns with techniques categorized under T1566 - Phishing and T1059 - Command and Scripting Interpreter, where attackers can use the XSS flaw to establish persistent access through malicious payloads that redirect users to compromised sites or harvest cookies and session tokens. The vulnerability can be exploited to create a chain of attacks where initial access through comment injection leads to session hijacking, privilege escalation, or data exfiltration. Additionally, since WordPress is widely deployed across various industries including financial services, healthcare, and government sectors, the potential for widespread impact is significant. The vulnerability affects not just individual blog owners but can compromise entire WordPress installations that rely on comment functionality, making it a critical concern for security administrators managing multiple sites or organizations with shared WordPress infrastructure.
Mitigation strategies for CVE-2017-18561 require immediate action to upgrade the vulnerable plugin to version 0.6 or later, where the XSS vulnerability has been patched. Organizations should implement comprehensive input validation and output encoding practices across all user-submitted content, particularly within comment systems and embedded media functionality. The remediation process should include thorough security auditing of all installed plugins to identify similar vulnerabilities, as well as implementing content security policies that restrict script execution within comment sections. Security measures should also encompass regular monitoring of plugin repositories for updates and vulnerabilities, along with maintaining updated security baselines that align with industry standards such as those defined by the OWASP Top Ten. Additionally, organizations should consider implementing web application firewalls that can detect and block suspicious script injection attempts, and establish incident response procedures specifically designed to address XSS vulnerabilities in content management systems.