CVE-2011-2421 in Shockwave Player
Summary
by MITRE
Dirapi.dll in Adobe Shockwave Player before 11.6.1.629 allows attackers to execute arbitrary code or cause a denial of service (memory corruption) via a crafted .dir media file.
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Analysis
by VulDB Data Team • 11/17/2021
Adobe Shockwave Player contains a critical memory corruption vulnerability in the dirapi.dll component that affects versions prior to 11.6.1.629. This vulnerability arises from insufficient input validation when processing specially crafted .dir media files, which are used by Shockwave Player to handle directory-based multimedia content. The flaw represents a classic buffer overflow condition where attacker-controlled data can overwrite adjacent memory locations, potentially leading to arbitrary code execution or system instability.
The technical implementation of this vulnerability stems from improper bounds checking within the directory parsing logic of the Shockwave Player runtime. When the player encounters a malformed .dir file, the dirapi.dll module fails to properly validate the size and structure of directory entries before attempting to process them. This allows attackers to craft malicious media files that, when opened by an affected Shockwave Player version, trigger memory corruption through stack smashing or heap corruption techniques. The vulnerability specifically affects the player's handling of directory structures within Shockwave content, making it particularly dangerous in environments where users might encounter untrusted Shockwave media files.
From an operational perspective, this vulnerability presents significant risk to organizations relying on Shockwave Player for multimedia content delivery. Attackers can exploit this weakness remotely by delivering malicious .dir files through web browsers or email attachments, potentially gaining full system control without user interaction. The memory corruption can manifest as either arbitrary code execution or denial of service conditions, making it a versatile attack vector. Organizations with legacy Shockwave deployments face particular exposure since many users continue to run outdated versions of the software, creating persistent attack surfaces for threat actors. The vulnerability's impact extends beyond individual systems to potentially compromise entire network infrastructures where Shockwave Player is widely deployed.
Mitigation strategies should prioritize immediate patch deployment to update Shockwave Player to version 11.6.1.629 or later, which contains the necessary fixes for the memory corruption issues. Organizations should also implement network-based controls such as web application firewalls and content filtering solutions to block malicious .dir files from reaching end-user systems. Additionally, security teams should consider disabling Shockwave Player in environments where it is not essential, particularly in high-security contexts. The vulnerability aligns with CWE-121 Stack-based Buffer Overflow and CWE-122 Heap-based Buffer Overflow classifications, and represents a technique commonly mapped to attack patterns in the ATT&CK framework under T1203 Exploitation for Execution and T1499 Endpoint Denial of Service. Regular security assessments should include scanning for outdated Shockwave Player installations, and incident response procedures should be updated to address potential exploitation of this vulnerability.