CVE-2017-5025 in Chrome
Summary
by MITRE
FFmpeg in Google Chrome prior to 56.0.2924.76 for Linux, Windows and Mac, failed to perform proper bounds checking, which allowed a remote attacker to potentially exploit heap corruption via a crafted video file.
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Analysis
by VulDB Data Team • 08/04/2020
The vulnerability identified as CVE-2017-5025 represents a critical heap corruption flaw within the FFmpeg multimedia framework that was integrated into Google Chrome browser versions prior to 56.0.2924.76 across multiple operating systems including Linux, Windows, and macOS. This issue stems from insufficient bounds checking mechanisms within the video decoding pipeline, specifically affecting how Chrome processes multimedia content through its embedded FFmpeg library. The vulnerability falls under the category of memory safety issues and aligns with CWE-129, which addresses insufficient bounds checking, making it particularly dangerous as it can be exploited remotely without user interaction. The flaw exists in the handling of crafted video files that contain maliciously constructed data structures, allowing attackers to manipulate memory layout during the decoding process.
Attackers could leverage this vulnerability by crafting specially designed video files that trigger the heap corruption when Chrome attempts to decode them. The exploitation occurs during the multimedia processing phase where the browser's FFmpeg component fails to validate the boundaries of memory allocations, leading to potential buffer overflows or underflows. This type of vulnerability maps directly to ATT&CK technique T1203, which involves exploitation of remote services through crafted input data, and specifically targets the browser's multimedia subsystem. The remote nature of this attack vector means that users could be compromised simply by visiting a malicious website or opening a malicious email attachment containing the crafted video content, making it particularly dangerous in phishing campaigns and drive-by download scenarios.
The operational impact of this vulnerability extends beyond simple browser compromise, as successful exploitation could lead to complete system control or data exfiltration. The heap corruption can potentially be leveraged to execute arbitrary code within the browser context, allowing attackers to bypass security restrictions and escalate privileges. Given that Chrome is one of the most widely used browsers globally, the potential attack surface is enormous, with millions of users potentially affected by this vulnerability. The exploitation requires no user interaction beyond visiting a malicious webpage, making it particularly effective for large-scale attacks. Security researchers have noted that such memory corruption vulnerabilities often serve as initial access vectors in more sophisticated attack chains, where the initial compromise leads to further exploitation of other system vulnerabilities. The vulnerability's classification as a remote code execution flaw makes it particularly concerning for enterprise environments where browser-based attacks are a primary threat vector.
Mitigation strategies for CVE-2017-5025 primarily involve immediate browser updates to Chrome version 56.0.2924.76 or later, which includes patches addressing the bounds checking deficiencies in the FFmpeg implementation. Organizations should also implement network-level protections such as content filtering and web application firewalls to prevent access to known malicious sites. Browser hardening measures including sandboxing, privilege separation, and strict content security policies can help limit the potential damage from successful exploitation attempts. Additionally, users should be educated about the risks of visiting untrusted websites and opening suspicious email attachments. The fix implemented by Google addressed the underlying bounds checking mechanism within the FFmpeg library, ensuring proper validation of memory boundaries during video file processing. Regular security updates and patch management programs should be maintained to protect against similar vulnerabilities in other multimedia frameworks and browser components. Security monitoring should include detection of unusual browser behavior and memory access patterns that could indicate exploitation attempts.