CVE-2004-0283 in Mailmgr
Summary
by MITRE
Mailmgr 1.2.3 allows local users to overwrite arbitrary files via a symlink attack on (1) /tmp/mailmgr.unsort, (2) /tmp/mailmgr.tmp, or (3) /tmp/mailmgr.sort.
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Analysis
by VulDB Data Team • 06/22/2018
The vulnerability identified as CVE-2004-0283 affects Mailmgr version 1.2.3, a mail management utility that suffers from a critical security flaw involving insecure temporary file handling. This issue enables local attackers to perform symlink attacks against specific temporary files within the /tmp directory, creating a significant privilege escalation vector. The vulnerability stems from the application's failure to properly validate or secure temporary file creation processes, allowing malicious users to manipulate the file system through symbolic link manipulation.
The technical flaw manifests when Mailmgr creates temporary files at predictable locations including /tmp/mailmgr.unsort, /tmp/mailmgr.tmp, and /tmp/mailmgr.sort. These temporary files are created without proper security checks or atomic operations, making them susceptible to race conditions and symlink attacks. An attacker can establish symbolic links with the same names before the application creates its temporary files, causing the application to write data to unintended locations. This behavior directly violates security principles related to temporary file handling and demonstrates a classic example of insecure file creation practices that fall under CWE-377.
The operational impact of this vulnerability is substantial as it allows local users to overwrite arbitrary files on the system with the privileges of the user running Mailmgr. This can lead to privilege escalation scenarios where attackers can modify system files, configuration data, or other sensitive files that the application has write access to. The vulnerability affects the integrity and confidentiality of the system since attackers can potentially overwrite critical system files, modify application behavior, or create backdoors through file manipulation. This type of attack is particularly dangerous in multi-user environments where different users may have varying privilege levels.
The attack vector for this vulnerability aligns with techniques documented in the MITRE ATT&CK framework under privilege escalation and persistence tactics. Specifically, it relates to techniques involving file system permissions and insecure temporary file creation. The vulnerability demonstrates how insecure temporary file handling can be exploited to achieve unauthorized system modifications. Organizations should implement proper file system permissions, use secure temporary file creation methods such as open() with O_EXCL flag, and ensure that temporary files are created in secure directories with appropriate access controls. Additionally, the vulnerability highlights the importance of input validation and proper file system security practices as outlined in various cybersecurity frameworks and standards.