CVE-2016-5310 in Message Gateway
Summary
by MITRE
The RAR file parser component in the AntiVirus Decomposer engine in Symantec Advanced Threat Protection: Network (ATP); Symantec Email Security.Cloud; Symantec Data Center Security: Server; Symantec Endpoint Protection (SEP) for Windows before 12.1.6 MP5; Symantec Endpoint Protection (SEP) for Mac; Symantec Endpoint Protection (SEP) for Linux before 12.1.6 MP6; Symantec Endpoint Protection for Small Business Enterprise (SEP SBE/SEP.Cloud); Symantec Endpoint Protection Cloud (SEPC) for Windows/Mac; Symantec Endpoint Protection Small Business Edition 12.1; CSAPI before 10.0.4 HF02; Symantec Protection Engine (SPE) before 7.0.5 HF02, 7.5.x before 7.5.4 HF02, 7.5.5 before 7.5.5 HF01, and 7.8.x before 7.8.0 HF03; Symantec Mail Security for Domino (SMSDOM) before 8.0.9 HF2.1, 8.1.x before 8.1.2 HF2.3, and 8.1.3 before 8.1.3 HF2.2; Symantec Mail Security for Microsoft Exchange (SMSMSE) before 6.5.8_3968140 HF2.3, 7.x before 7.0_3966002 HF2.1, and 7.5.x before 7.5_3966008 VHF2.2; Symantec Protection for SharePoint Servers (SPSS) before SPSS_6.0.3_To_6.0.5_HF_2.5 update, 6.0.6 before 6.0.6 HF_2.6, and 6.0.7 before 6.0.7_HF_2.7; Symantec Messaging Gateway (SMG) before 10.6.2; Symantec Messaging Gateway for Service Providers (SMG-SP) before 10.5 patch 260 and 10.6 before patch 259; Symantec Web Gateway; and Symantec Web Security.Cloud allows remote attackers to cause a denial of service (memory corruption) via a crafted RAR file that is mishandled during decompression.
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Analysis
by VulDB Data Team • 01/11/2025
The vulnerability described in CVE-2016-5310 represents a critical memory corruption flaw within the RAR file parsing functionality of multiple Symantec security products. This issue affects a broad ecosystem of endpoint protection, email security, and web gateway solutions, creating widespread potential for denial of service attacks. The vulnerability stems from improper handling of crafted RAR archive files during the decompression process, where the AntiVirus Decomposer engine fails to properly validate or manage memory allocation when processing malformed archive structures. This memory corruption vulnerability manifests as a denial of service condition that can potentially crash the affected security appliances or systems, rendering them unavailable to protect against legitimate threats.
The technical implementation of this vulnerability involves the RAR file parser component within Symantec's AntiVirus Decomposer engine, which is responsible for extracting content from compressed archives as part of threat detection processes. When a maliciously crafted RAR file is processed, the decompression routine does not adequately validate the archive structure or manage memory resources, leading to buffer overflows or other memory corruption conditions. The flaw specifically occurs during the decompression phase where the parser attempts to allocate memory for extracted file data without proper bounds checking or sanitization of input parameters. This type of vulnerability is classified as a memory corruption issue that aligns with CWE-121, which covers stack-based buffer overflow conditions, and CWE-122, which addresses heap-based buffer overflows. The vulnerability is particularly concerning because it operates within the core decompression engine that processes files as part of normal security operations, making it exploitable through legitimate file processing workflows.
From an operational perspective, this vulnerability creates significant risk for organizations relying on Symantec security solutions, as attackers can remotely trigger system crashes through carefully constructed RAR files. The impact extends across multiple product lines including endpoint protection for windows, mac, and linux platforms, as well as email security appliances, web gateways, and messaging security solutions. Attackers could leverage this vulnerability to disrupt security operations by causing denial of service conditions on critical infrastructure, potentially leading to gaps in threat detection coverage while the affected systems are offline. The vulnerability affects both on-premises deployments and cloud-based services, including Symantec Endpoint Protection Cloud, Symantec Email Security.Cloud, and Symantec Web Security.Cloud, making it a systemic risk across the entire Symantec security portfolio. According to ATT&CK framework, this vulnerability maps to T1499.004 (Endpoint Denial of Service) and T1566.001 (Phishing with Malicious Attachment), as it enables remote attackers to cause service disruption through malicious file attachments that exploit the decompression engine.
The remediation strategy for CVE-2016-5310 requires immediate deployment of vendor patches across all affected Symantec products, with specific attention to version numbers and hotfix releases. Organizations should prioritize patching their endpoint protection systems, email security appliances, and web gateways, as these represent the most critical attack vectors. The vulnerability affects multiple versions of Symantec Endpoint Protection including 12.1.6 MP5 for Windows, 12.1.6 MP6 for Linux, and various releases of the Protection Engine, Mail Security products, and Messaging Gateway solutions. Security teams should implement network monitoring to detect potential exploitation attempts, particularly when analyzing email traffic or file transfers that might contain RAR attachments. The mitigation approach should include both immediate patch deployment and implementation of additional controls such as email filtering rules that block RAR file attachments or restrict decompression of suspicious archives. Organizations should also consider implementing network segmentation to limit the potential impact of exploitation and maintain comprehensive logging of file processing activities to detect anomalous behavior that might indicate attempted exploitation of this vulnerability.