CVE-2008-4698 in Web Browser
Summary
by MITRE
Opera before 9.61 does not properly block scripts during preview of a news feed, which allows remote attackers to create arbitrary new feed subscriptions and read the contents of arbitrary feeds.
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Analysis
by VulDB Data Team • 05/25/2025
This vulnerability exists in Opera web browsers prior to version 9.61 and represents a significant security flaw in the browser's feed preview functionality. The issue stems from insufficient input validation and sanitization during the processing of news feeds, specifically when the browser attempts to display feed content in a preview mode. Attackers can exploit this weakness by crafting malicious feed content that bypasses the browser's intended security restrictions. The vulnerability allows remote threat actors to manipulate the feed subscription process and access content from arbitrary feeds that would normally be restricted or filtered by the browser's security model. This represents a classic case of improper access control where the feed preview mechanism fails to properly isolate potentially malicious content from the user's feed management system. The flaw enables attackers to not only subscribe users to unwanted feeds but also to read and potentially exfiltrate the contents of feeds that the user might not have intended to access.
The technical implementation of this vulnerability involves the browser's feed preview subsystem failing to properly sanitize or validate feed data before rendering it in a context where script execution might occur. When Opera processes feed content for preview, it should maintain strict separation between the feed data and the browser's feed management functions. However, the vulnerability allows attackers to inject malicious feed entries that can trigger unintended behavior in the preview mechanism. This could involve embedding javascript code or other executable content within feed elements that are then processed without proper security checks. The flaw essentially creates a pathway where feed preview functionality becomes a vector for unauthorized feed subscription manipulation and content access. From a cybersecurity perspective, this vulnerability demonstrates poor input validation practices and inadequate sandboxing of feed content processing, which are fundamental security principles that should prevent such cross-contamination between different functional components of a browser.
The operational impact of this vulnerability extends beyond simple feed manipulation to potentially enable more sophisticated attacks. An attacker could use this vulnerability to subscribe users to malicious feeds that might contain phishing content or other harmful material. Additionally, the ability to read arbitrary feed contents could allow for information gathering and reconnaissance activities, particularly if the feeds contain sensitive or proprietary information. The vulnerability could be exploited in combination with other attack vectors to create more complex threats, such as feed-based phishing campaigns or information leakage attacks. Users who regularly access news feeds through Opera would be at risk, particularly in environments where feed content might contain confidential information or where attackers could leverage the feed subscription functionality to establish persistence. This vulnerability also highlights the broader risk of feed processing in web browsers and the need for comprehensive security measures when handling external content sources.
Mitigation strategies for this vulnerability should focus on implementing proper feed validation and sanitization mechanisms within the browser's feed processing pipeline. Browser vendors should ensure that feed preview functionality properly isolates feed content from the core feed management system and implements strict input validation for all feed elements. Users should be encouraged to update to Opera version 9.61 or later, where this vulnerability has been addressed through improved feed processing controls. Organizations should also implement network-level monitoring to detect unusual feed subscription patterns that might indicate exploitation attempts. From a defensive perspective, this vulnerability aligns with common attack patterns described in the attack technique matrix under techniques related to feed manipulation and content injection. The vulnerability maps to CWE-20, which describes improper input validation, and could be addressed through defensive coding practices that emphasize proper sanitization of external content before processing. Security teams should also consider implementing feed filtering policies and monitoring for suspicious feed activity as part of their overall browser security posture. The remediation process should include comprehensive testing of feed preview functionality to ensure that similar vulnerabilities do not exist in other external content processing mechanisms within the browser.