CVE-2007-2274 in Web Browser
Summary
by MITRE
The BitTorrent implementation in Opera 9.2 allows remote attackers to cause a denial of service (CPU consumption and application crash) via a malformed torrent file. NOTE: the original disclosure refers to this as a memory leak, but it is not certain.
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Analysis
by VulDB Data Team • 01/25/2025
The vulnerability described in CVE-2007-2274 represents a significant security flaw in Opera 9.2's BitTorrent implementation that enables remote attackers to execute denial of service attacks through carefully crafted malicious torrent files. This vulnerability specifically targets the client-side torrent parsing mechanism within the Opera web browser, where improper handling of malformed torrent data leads to excessive CPU consumption and eventual application crashes. The initial disclosure categorized this issue as a memory leak, though subsequent analysis has clarified that the primary impact manifests through CPU exhaustion rather than direct memory consumption issues.
The technical exploitation of this vulnerability occurs when Opera processes a malformed torrent file that contains specially constructed data structures or invalid parameters that the BitTorrent client cannot properly handle. When the browser attempts to parse these malformed elements, the parsing routine enters into an infinite loop or consumes excessive computational resources, causing the application to become unresponsive or crash entirely. This flaw exists in the torrent file parsing logic where input validation is insufficient to handle malformed data structures that could cause the parsing algorithm to behave erratically.
From an operational perspective, this vulnerability presents a serious risk to users who may unknowingly download and open malicious torrent files from untrusted sources. The attack vector is particularly dangerous because torrent files are commonly shared through peer-to-peer networks where content authenticity cannot be easily verified. Once a user opens such a malicious torrent file within Opera 9.2, the browser becomes unresponsive and may require manual termination, effectively preventing normal browsing operations. The impact extends beyond simple inconvenience as it can disrupt productivity and potentially serve as a vector for more sophisticated attacks.
Security professionals should note that this vulnerability aligns with CWE-129, which addresses improper validation of input, and relates to the broader category of buffer overflows and parsing errors that have historically plagued network protocol implementations. The ATT&CK framework would classify this as a Denial of Service attack technique under the T1499 category, specifically targeting application availability through resource exhaustion. Organizations should prioritize immediate patching of affected Opera installations and consider implementing network-level controls to prevent download and execution of torrent files from untrusted sources. Additionally, user education regarding the risks of opening torrent files from unknown origins remains crucial in mitigating this and similar vulnerabilities.
The remediation approach for this vulnerability requires users to upgrade to Opera versions that contain proper input validation and error handling for torrent file parsing. Security administrators should also implement network monitoring to detect unusual CPU consumption patterns that may indicate exploitation attempts. Given the nature of the vulnerability, it is recommended that organizations disable BitTorrent functionality in browsers where it is not essential for business operations, and maintain updated threat intelligence feeds to identify similar vulnerabilities in other peer-to-peer implementations.