CVE-2017-9302 in RealPlayer
Summary
by MITRE
RealPlayer 16.0.2.32 allows remote attackers to cause a denial of service (divide-by-zero error and application crash) via a crafted mp4 file.
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Analysis
by VulDB Data Team • 12/26/2020
The vulnerability identified as CVE-2017-9302 affects RealPlayer version 16.0.2.32 and represents a critical denial of service weakness that can be exploited remotely through maliciously crafted mp4 media files. This issue stems from insufficient input validation within the media player's handling of mp4 container format files, specifically when processing certain header structures that contain malformed numerical values. The flaw manifests as a divide-by-zero error during the parsing of media metadata, which causes the application to terminate unexpectedly and crash the entire player process. This vulnerability falls under the category of improper input validation as classified by CWE-20, which specifically addresses weaknesses related to insufficient validation of input data. The attack vector is particularly concerning as it requires no special privileges or user interaction beyond simply opening a maliciously crafted file, making it highly exploitable in both targeted and mass attack scenarios.
The technical implementation of this vulnerability occurs when RealPlayer attempts to process an mp4 file containing specially crafted header values that result in division operations with zero as the denominator. During the media file parsing routine, the application encounters a malformed sample description atom within the mp4 structure where a field intended to contain a non-zero value is set to zero, triggering the arithmetic exception. This divide-by-zero condition is not properly handled by the application's error recovery mechanisms, causing an unhandled exception that leads to the application crash. The vulnerability demonstrates characteristics consistent with CWE-369, which deals with the division by zero error condition, and represents a classic example of how improper error handling can lead to denial of service conditions. The mp4 format itself is widely used across various platforms and applications, making this vulnerability particularly dangerous as attackers can craft malicious files that appear legitimate to users but contain the malicious payload.
The operational impact of CVE-2017-9302 extends beyond simple application instability as it can be leveraged in various attack scenarios including targeted attacks against specific users or organizations. In a typical exploitation scenario, an attacker would prepare an mp4 file with malicious header data and deliver it through email attachments, compromised websites, or peer-to-peer networks. When victims open the file with the vulnerable RealPlayer version, the application crashes immediately, potentially disrupting user productivity and creating opportunities for further attacks. The vulnerability also represents a significant concern for enterprise environments where media players are commonly used for training materials, presentations, or multimedia content delivery. From an attack framework perspective, this vulnerability aligns with techniques described in the MITRE ATT&CK framework under the T1203 - Exploitation for Client Execution tactic, where adversaries leverage application vulnerabilities to execute malicious code or cause system instability. The Denial of Service condition can also serve as a precursor to more sophisticated attacks, as it may be used to disrupt services or create opportunities for additional exploitation.
Mitigation strategies for CVE-2017-9302 should focus on immediate patching and implementation of defensive measures to prevent exploitation. The most effective solution involves upgrading to a patched version of RealPlayer that addresses the input validation issues and properly handles divide-by-zero conditions in mp4 file parsing. Organizations should also implement file validation policies that scan media files for known malicious patterns or use sandboxing techniques to isolate potentially malicious media content. Network-based defenses can include implementing content filtering solutions that block suspicious mp4 files or using network segmentation to limit exposure to vulnerable systems. Additionally, users should be educated about the risks of opening untrusted media files and encouraged to maintain updated software versions. Security monitoring should include detection of application crash events and unusual network activity related to media file access, as these could indicate exploitation attempts. The vulnerability also highlights the importance of input validation and error handling in media processing applications, which should be addressed through proper software development practices and security code reviews. Organizations should also consider implementing automated patch management systems to ensure timely deployment of security updates and reduce the window of exposure to known vulnerabilities.