CVE-2022-4876 in mwEmbed
Summary
by MITRE • 01/09/2023
A vulnerability was found in Kaltura mwEmbed up to 2.96.rc1 and classified as problematic. This issue affects some unknown processing of the file includes/DefaultSettings.php. The manipulation of the argument HTTP_X_FORWARDED_HOST leads to cross site scripting. The attack may be initiated remotely. Upgrading to version 2.96.rc2 is able to address this issue. The name of the patch is 13b8812ebc8c9fa034eed91ab35ba8423a528c0b. It is recommended to upgrade the affected component. The associated identifier of this vulnerability is VDB-217427.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 01/28/2023
The vulnerability identified as CVE-2022-4876 represents a cross-site scripting flaw within the Kaltura mwEmbed media player library, specifically affecting versions up to 2.96.rc1. This security issue stems from improper handling of the HTTP_X_FORWARDED_HOST HTTP header within the includes/DefaultSettings.php file, creating a pathway for malicious actors to inject arbitrary web scripts into web applications. The vulnerability operates under the Common Weakness Enumeration framework as CWE-79, which categorizes it as a cross-site scripting weakness, making it particularly dangerous for web applications that process user input without proper sanitization. The attack vector is remote, meaning that an attacker can exploit this vulnerability without requiring physical access to the target system, making it highly accessible to threat actors operating from external networks.
The technical exploitation of this vulnerability occurs when the application processes the HTTP_X_FORWARDED_HOST header without adequate input validation or output encoding, allowing maliciously crafted host values to be reflected in the application's response. This reflected XSS vulnerability enables attackers to execute malicious scripts in the context of a victim's browser, potentially leading to session hijacking, credential theft, or redirection to malicious websites. The flaw specifically manifests in the DefaultSettings.php file, which serves as a critical configuration component for the media player, making it a prime target for exploitation. The vulnerability's designation as "problematic" in the original classification indicates that it represents a significant security risk that requires immediate attention and remediation.
The operational impact of this vulnerability extends beyond simple script execution, as it can potentially compromise the integrity and confidentiality of user sessions within the Kaltura media platform. When an attacker successfully exploits this XSS vulnerability, they can manipulate the media player's behavior to perform unauthorized actions, such as stealing authentication tokens, modifying media playback settings, or redirecting users to phishing sites. The affected Kaltura mwEmbed library is widely used in enterprise environments and educational institutions, amplifying the potential scope of impact. The vulnerability's presence in the default settings configuration file suggests that even basic installations could be at risk, as the flaw does not require specific user interaction beyond the normal HTTP request processing. The security implications are particularly concerning given that the HTTP_X_FORWARDED_HOST header is commonly used in load-balanced environments and reverse proxy configurations, making the vulnerability more prevalent in production systems.
The recommended remediation strategy involves upgrading to version 2.96.rc2, which contains the patch identified by the commit hash 13b8812ebc8c9fa034eed91ab35ba8423a528c0b. This upgrade addresses the root cause by implementing proper input sanitization and output encoding for the HTTP_X_FORWARDED_HOST header processing. The patch aligns with the ATT&CK framework's T1566.001 technique, which involves the exploitation of web application vulnerabilities to execute malicious code, and the remediation directly counteracts this threat by closing the input validation gap. Organizations should also implement additional defensive measures such as input validation at multiple layers, output encoding for all user-controllable data, and web application firewalls that can detect and block suspicious HTTP headers. The vulnerability's classification under VDB-217427 provides a unique identifier for tracking and mitigation efforts, ensuring that security teams can properly prioritize and address this specific threat within their vulnerability management processes.