CVE-2018-4935 in Flash Player
Summary
by MITRE
Adobe Flash Player versions 29.0.0.113 and earlier have an exploitable out-of-bounds write vulnerability. Successful exploitation could lead to arbitrary code execution in the context of the current user.
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Analysis
by VulDB Data Team • 12/28/2024
Adobe Flash Player contained a critical out-of-bounds write vulnerability that affected versions 29.0.0.113 and earlier, representing a severe security flaw that could be exploited to execute arbitrary code on affected systems. This vulnerability stems from improper bounds checking within the Flash Player's handling of multimedia content, particularly when processing specially crafted SWF files or embedded Flash objects. The flaw allows attackers to write data beyond the allocated memory boundaries, potentially corrupting adjacent memory regions and enabling privilege escalation. The vulnerability is categorized under CWE-787, which specifically addresses out-of-bounds write conditions that can lead to memory corruption and arbitrary code execution.
The technical exploitation of this vulnerability typically involves crafting malicious Flash content that triggers the memory corruption when the player attempts to process the malformed data. Attackers can leverage this flaw through various attack vectors including web browsers that have Flash Player enabled, email attachments containing embedded Flash content, or malicious websites that automatically execute Flash-based exploits. The out-of-bounds write occurs during the parsing of multimedia elements within Flash Player's memory management system, where insufficient validation allows memory addresses to be overwritten with attacker-controlled data. This memory corruption can overwrite critical program structures such as function pointers or return addresses, enabling attackers to redirect execution flow and inject malicious code into the running Flash Player process.
The operational impact of this vulnerability extends beyond simple code execution, as it represents a complete compromise of the affected system's security posture. Successful exploitation allows attackers to execute arbitrary code with the privileges of the current user, potentially leading to full system compromise, data exfiltration, or establishment of persistent backdoors. The vulnerability's exploitation requires minimal user interaction, often only visiting a malicious website or opening a compromised email attachment, making it particularly dangerous in enterprise environments where users frequently access untrusted web content. The attack surface is significantly broadened by Flash Player's widespread deployment across various operating systems and browsers, creating numerous potential entry points for adversaries.
Security professionals should implement immediate mitigations including disabling Flash Player in all web browsers and removing the plugin entirely from systems where it is not absolutely required for legacy applications. The recommended approach aligns with ATT&CK technique T1059.007, which involves using scripting languages for execution, by ensuring that the Flash runtime environment is completely eliminated to prevent exploitation. Organizations should also deploy network-based protections such as web application firewalls and content filtering solutions that can detect and block Flash-based attack vectors. Additionally, regular security updates and patch management procedures should be enforced to ensure that any remaining Flash installations are kept current with the latest security patches. The vulnerability demonstrates the critical importance of maintaining up-to-date security controls and the risks associated with legacy software that is no longer supported by vendors, as Adobe officially discontinued Flash Player support in 2020.