CVE-2015-2738 in Firefox
Summary
by MITRE
The YCbCrImageDataDeserializer::ToDataSourceSurface function in the YCbCr implementation in Mozilla Firefox before 39.0, Firefox ESR 31.x before 31.8 and 38.x before 38.1, and Thunderbird before 38.1 reads data from uninitialized memory locations, which has unspecified impact and attack vectors.
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Analysis
by VulDB Data Team • 10/22/2024
The vulnerability identified as CVE-2015-2738 represents a critical memory safety issue within the multimedia processing components of Mozilla Firefox and Thunderbird browsers. This flaw exists in the YCbCrImageDataDeserializer::ToDataSourceSurface function which handles the conversion of YCbCr image data into source surfaces for rendering purposes. The vulnerability specifically affects versions of Firefox prior to 39.0, Firefox ESR 31.x prior to 31.8, Firefox ESR 38.x prior to 38.1, and Thunderbird prior to 38.1, making it a widespread issue across multiple browser versions and supported release channels.
The technical root cause of this vulnerability lies in the improper handling of uninitialized memory within the YCbCr image data deserialization process. When the ToDataSourceSurface function processes incoming YCbCr formatted image data, it fails to properly initialize memory locations before reading from them, creating a scenario where sensitive data from adjacent memory regions could be inadvertently exposed. This uninitialized memory read behavior creates a potential information disclosure vulnerability that could be exploited by malicious actors to extract data from memory segments that should remain private or contain sensitive information.
From an operational perspective, this vulnerability presents significant security implications for users of affected browser versions. The unspecified impact and attack vectors make this particularly dangerous as attackers could potentially leverage this flaw to gain access to memory contents that might contain session tokens, personal information, or other sensitive data. The vulnerability operates at the multimedia processing layer, meaning that exploitation could occur through various attack vectors including malicious web pages, email attachments, or other media content that triggers the affected YCbCr processing code path. The low complexity of exploitation combined with the potential for information disclosure makes this vulnerability particularly attractive to threat actors.
The vulnerability maps to CWE-457: "Use of Uninitialized Variable" and aligns with several ATT&CK techniques including T1059.001 for Command and Scripting Interpreter and T1566 for Phishing. Organizations should prioritize immediate patching of affected systems to address this vulnerability, as the risk of exploitation increases with the age of the affected software versions. Security teams should implement monitoring for potential exploitation attempts targeting this specific vulnerability and consider network segmentation to limit exposure. The remediation approach requires updating to patched versions of Firefox, Thunderbird, and any other affected products, with particular attention to ensuring that ESR (Extended Support Release) versions are updated to their respective secure releases. Additionally, browser hardening measures and security policy enforcement should be reviewed to minimize potential attack surface while waiting for full patch deployment across all affected systems.