CVE-2018-19516 in Applications
Summary
by MITRE
messagepartthemes/default/defaultrenderer.cpp in messagelib in KDE Applications before 18.12.0 does not properly restrict the handling of an http-equiv="REFRESH" value.
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Analysis
by VulDB Data Team • 04/13/2024
The vulnerability identified as CVE-2018-19516 resides within the messagepartthemes/default/defaultrenderer.cpp component of KDE Applications messaging library known as messagelib. This flaw affects versions prior to 18.12.0 and represents a critical security issue that could potentially allow malicious actors to manipulate how web content is rendered within email messages. The vulnerability specifically targets the improper handling of http-equiv="REFRESH" attributes which are commonly used in HTML documents to automatically redirect users to different web pages after a specified time interval. When processing email content that contains such refresh directives, the affected software fails to adequately validate or sanitize the refresh values, creating a potential attack surface for malicious actors.
This security weakness enables attackers to craft malicious email messages that contain specially formatted http-equiv="REFRESH" tags with arbitrary URLs or commands. The improper restriction allows the application to process these refresh directives without sufficient validation, potentially leading to unauthorized redirection of users to malicious websites or execution of unintended commands. The vulnerability falls under the category of improper input validation as defined by CWE-20, which occurs when a program does not properly validate or sanitize input data before processing it. This type of flaw commonly enables various attack vectors including cross-site scripting, phishing, and unauthorized content redirection.
The operational impact of this vulnerability extends beyond simple content rendering issues as it can be exploited to perform sophisticated social engineering attacks. When users open affected email messages, the malicious refresh directives could automatically redirect them to phishing pages designed to capture credentials or personal information. The vulnerability particularly affects email clients and applications that display HTML content from untrusted sources, making it a significant concern for enterprise email systems and personal email clients that process rich text messages. Security researchers have noted that this type of vulnerability is especially dangerous in environments where users frequently access email from untrusted sources or where email clients automatically render HTML content without user confirmation.
Mitigation strategies for CVE-2018-19516 should prioritize immediate patching of affected KDE Applications installations to version 18.12.0 or later where the vulnerability has been resolved. Organizations should also implement email filtering rules that block or flag messages containing suspicious http-equiv refresh directives, particularly those with external URLs or unusual refresh intervals. Network administrators should consider implementing additional security layers such as web application firewalls that can detect and block malicious refresh attempts. From a defensive perspective, this vulnerability aligns with tactics described in the MITRE ATT&CK framework under the T1566 category for Phishing, as it enables attackers to create convincing phishing campaigns that leverage automatic redirection capabilities. The remediation process should include comprehensive testing of patched environments to ensure that the fix properly handles all variants of refresh directives while maintaining legitimate functionality for normal email processing operations.