CVE-2018-4871 in Flash Player
Summary
by MITRE
An Out-of-bounds Read issue was discovered in Adobe Flash Player before 28.0.0.137. This vulnerability occurs because of computation that reads data that is past the end of the target buffer. The use of an invalid (out-of-range) pointer offset during access of internal data structure fields causes the vulnerability. A successful attack can lead to sensitive data exposure.
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Analysis
by VulDB Data Team • 01/20/2023
The vulnerability identified as CVE-2018-4871 represents a critical out-of-bounds read flaw in Adobe Flash Player versions prior to 28.0.0.137, classified under CWE-125 as an "Out-of-bounds Read" condition. This issue stems from improper bounds checking during memory access operations within the player's internal data structures, creating a scenario where the application attempts to read data beyond the allocated buffer boundaries. The flaw manifests when the Flash Player processes multimedia content that triggers computation logic involving invalid pointer offsets, leading to memory access violations that can be exploited by malicious actors.
The technical exploitation of this vulnerability occurs through carefully crafted Flash content that manipulates the player's internal state to force memory access beyond legitimate buffer limits. When the Flash Player encounters such malformed input, it attempts to access memory locations that are outside the intended data structure boundaries, resulting in the exposure of sensitive information stored in adjacent memory regions. This type of vulnerability falls under the ATT&CK technique T1059.007 for "Command and Scripting Interpreter: JavaScript' and T1566.001 for "Phishing: Spearphishing Attachment', as attackers can leverage this flaw through malicious Flash files delivered via email attachments or compromised websites. The out-of-bounds read condition creates a pathway for information disclosure, potentially exposing cryptographic keys, user credentials, or other confidential data stored in memory.
The operational impact of CVE-2018-4871 extends beyond simple data exposure, as it represents a fundamental memory safety issue that can serve as a stepping stone for more sophisticated attacks. Attackers can leverage this vulnerability to perform information gathering operations, potentially extracting sensitive data that could be used for further exploitation or lateral movement within compromised systems. The vulnerability's exploitation typically requires user interaction with malicious Flash content, making it particularly dangerous in environments where Flash Player remains active despite its known security issues. Organizations relying on legacy Flash content may find themselves vulnerable to this class of attack, especially when dealing with older versions of the player that lack proper bounds checking mechanisms.
Mitigation strategies for CVE-2018-4871 primarily focus on immediate remediation through patch management, requiring organizations to update to Adobe Flash Player version 28.0.0.137 or later, which includes fixed bounds checking logic and memory access validation. System administrators should implement comprehensive patch deployment processes to ensure all endpoints running Flash Player are updated promptly, as the vulnerability remains exploitable in older versions. Additionally, organizations should consider implementing network-level controls to block Flash content delivery and disable Flash Player plugins entirely, aligning with industry best practices for reducing attack surface. The remediation approach should also include monitoring for exploitation attempts through network traffic analysis and endpoint detection systems that can identify malicious Flash content delivery patterns, as outlined in the ATT&CK framework's detection methodologies for command and scripting interpreter techniques.