CVE-2012-1916 in AtMail Open
Summary
by MITRE
@Mail WebMail Client in AtMail Open-Source before 1.05 allows remote attackers to execute arbitrary code via an e-mail attachment with an executable extension, leading to the creation of an executable file under tmp/.
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Analysis
by VulDB Data Team • 08/09/2024
The CVE-2012-1916 vulnerability affects the AtMail Open-Source WebMail Client version 1.04 and earlier, representing a critical security flaw that enables remote code execution through email attachments. This vulnerability resides in the email client's handling of file attachments, specifically when processing executable files with extensions such as .exe, .bat, .cmd, and other potentially malicious file types. The flaw stems from inadequate input validation and sanitization mechanisms within the webmail client's attachment processing pipeline, which fails to properly validate or restrict file types before allowing their storage in temporary directories.
The technical implementation of this vulnerability occurs when a remote attacker crafts a malicious email containing an attachment with an executable extension and sends it to a victim using the vulnerable AtMail WebMail Client. Upon the victim opening or previewing the email, the webmail client processes the attachment and creates an executable file in the tmp/ directory without proper validation. This process bypasses normal security controls that should prevent execution of potentially malicious files, allowing the attacker to execute arbitrary code on the target system with the privileges of the webmail service account. The vulnerability directly maps to CWE-22 Improper Limitation of a Pathname to a Restricted Directory and CWE-74 Improper Neutralization of Special Elements in Output Used by a Downstream Component, both of which are fundamental security weaknesses in file handling and path validation.
The operational impact of CVE-2012-1916 is severe and far-reaching, as it provides attackers with a straightforward method to compromise systems running vulnerable AtMail WebMail Client installations. Successful exploitation can lead to full system compromise, allowing attackers to establish persistent access, escalate privileges, and potentially use the compromised system as a launch point for further attacks within the network. The vulnerability is particularly dangerous because it requires minimal user interaction beyond simply receiving the malicious email, making it an effective vector for phishing campaigns and social engineering attacks. The attack surface is broad as any user with access to the vulnerable webmail client can be targeted, and the attack can be executed entirely through email without requiring additional network access or specialized tools.
Security professionals should implement multiple layers of defense to mitigate this vulnerability, starting with immediate patching of all AtMail Open-Source installations to version 1.05 or later, which contains the necessary security fixes. Additionally, organizations should implement strict email filtering policies that block executable attachments at the email gateway level, preventing malicious files from reaching users entirely. Network segmentation and privilege separation should be enforced to limit the potential impact of successful exploitation, ensuring that the webmail service operates with minimal required privileges. The mitigation strategy should also include monitoring for unauthorized file creation in temporary directories and implementing host-based intrusion detection systems to identify suspicious file operations. This vulnerability aligns with ATT&CK technique T1193 Spearphishing Attachment, where adversaries use email attachments to deliver malware, and T1059 Command and Scripting Interpreter, where attackers execute code through compromised systems. Organizations should also consider implementing email security solutions that can detect and block suspicious file types before they reach end users, as well as conducting regular security awareness training to help users recognize and avoid potentially malicious email attachments.