CVE-2025-42599 in Active Mail
Summary
by MITRE • 04/18/2025
Active! mail 6 BuildInfo: 6.60.05008561 and earlier contains a stack-based buffer overflow vulnerability. Receiving a specially crafted request created and sent by a remote unauthenticated attacker may lead to arbitrary code execution and/or a denial-of-service (DoS) condition.
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Analysis
by VulDB Data Team • 10/22/2025
The vulnerability identified as CVE-2025-42599 affects Active! mail 6 version 6.60.05008561 and earlier installations, representing a critical stack-based buffer overflow flaw that poses significant security risks to affected systems. This vulnerability resides within the email server software's processing logic for incoming requests, creating a pathway for remote attackers to exploit the system through specially crafted malicious payloads. The flaw specifically manifests when the application receives malformed input during request handling, allowing attackers to overwrite adjacent memory locations on the stack through buffer overflow techniques.
The technical implementation of this vulnerability follows the characteristics of CWE-121 stack-based buffer overflow, where insufficient bounds checking enables an attacker to write beyond the allocated buffer space and potentially overwrite critical program execution elements such as return addresses, function pointers, or other stack variables. This type of vulnerability is particularly dangerous because it can be exploited without authentication requirements, making it accessible to any remote attacker who can send requests to the vulnerable system. The exploitation process typically involves crafting a malicious request that exceeds the buffer capacity, causing the overflow to overwrite the stack frame and potentially redirect program execution to malicious code injected by the attacker.
The operational impact of this vulnerability extends beyond simple code execution capabilities to include potential denial-of-service conditions that can render the email server completely unavailable to legitimate users. When exploited successfully, the buffer overflow can cause the application to crash or behave unpredictably, leading to service disruption that affects email communication for affected organizations. The remote unauthenticated nature of the attack means that organizations cannot rely on network-level access controls or authentication mechanisms to prevent exploitation, as the vulnerability can be triggered from outside the network perimeter. This makes the vulnerability particularly concerning for email servers that are exposed to the internet and serve as critical communication infrastructure for businesses and organizations.
Organizations should prioritize immediate mitigation efforts including applying available vendor patches or updates to resolve the buffer overflow vulnerability in Active! mail 6 installations. System administrators should also implement network segmentation and access controls to limit exposure of vulnerable systems to untrusted networks. Monitoring network traffic for suspicious patterns and implementing intrusion detection systems can help identify exploitation attempts. The vulnerability's classification under the attack phase of execution in the MITRE ATT&CK framework indicates that exploitation involves direct manipulation of program execution flow, making defensive measures critical for maintaining system integrity and preventing unauthorized access to email infrastructure. Additionally, regular security assessments and vulnerability scanning should be conducted to identify other potential weaknesses in the email server environment that could be leveraged in conjunction with this primary vulnerability.