CVE-2018-16530 in Email Security
Summary
by MITRE
A stack-based buffer overflow in Forcepoint Email Security version 8.5 allows an attacker to craft malicious input and potentially crash a process creating a denial-of-service. While no known Remote Code Execution (RCE) vulnerabilities exist, as with all buffer overflows, the possibility of RCE cannot be completely ruled out. Data Execution Protection (DEP) is already enabled on the Email appliance as a risk mitigation.
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Analysis
by VulDB Data Team • 08/28/2023
The vulnerability identified as CVE-2018-16530 represents a critical stack-based buffer overflow within Forcepoint Email Security version 8.5, specifically affecting the email appliance's processing capabilities. This flaw resides in the application's handling of user-supplied input, where insufficient bounds checking allows maliciously crafted data to overflow allocated memory buffers on the stack. The vulnerability demonstrates characteristics consistent with CWE-121, stack-based buffer overflow, where the attacker can manipulate the program's execution flow by overwriting adjacent stack memory locations including return addresses and function parameters.
The technical implementation of this vulnerability occurs when the email appliance processes incoming email messages or configuration data that contains specially crafted payloads designed to exceed the allocated buffer size. When the system attempts to store this oversized input in a fixed-size stack buffer, the excess data overflows into adjacent memory regions, potentially corrupting the stack frame and disrupting normal program execution. The exploitation vector typically involves sending malformed email content or configuration parameters that trigger the vulnerable code path during message processing or parsing operations.
The operational impact of this vulnerability manifests primarily as a denial-of-service condition, where successful exploitation can cause the targeted email security appliance to crash or become unresponsive, effectively disrupting email services for the organization. While the current analysis indicates no confirmed remote code execution capabilities exist within this specific vulnerability, the nature of stack-based buffer overflows creates a significant risk surface that could potentially be leveraged for more advanced exploitation techniques. The presence of Data Execution Protection (DEP) on the appliance provides some mitigation against direct code execution, as this security feature prevents execution of code placed in data segments of memory, though it does not completely eliminate the risk of exploitation.
Organizations should implement immediate mitigations including applying the vendor-provided security patches and updates released for Forcepoint Email Security version 8.5 to address this vulnerability. Network segmentation and monitoring should be enhanced to detect potential exploitation attempts through anomalous email traffic patterns or malformed message deliveries. The implementation of additional security controls such as email content filtering, sandboxing of suspicious attachments, and regular vulnerability assessments will help reduce the attack surface. According to ATT&CK framework, this vulnerability maps to T1203 - Exploitation for Client Execution and T1499 - Endpoint Denial of Service, representing both the initial exploitation phase and the resulting service disruption impact on the targeted email infrastructure.