CVE-2010-0301 in maildrop
Summary
by MITRE
main.C in maildrop 2.3.0 and earlier, when run by root with the -d option, uses the gid of root for execution of the .mailfilter file in a user's home directory, which allows local users to gain privileges via a crafted file.
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Analysis
by VulDB Data Team • 04/30/2026
The vulnerability described in CVE-2010-0301 represents a critical privilege escalation flaw within the maildrop mail processing utility version 2.3.0 and earlier. This issue specifically manifests when maildrop is executed with root privileges using the -d command line option, which is commonly employed for directory-based mail filtering operations. The flaw stems from improper privilege handling during the execution of user-specific filter files, creating a dangerous condition where local attackers can manipulate system permissions to elevate their access level.
The technical mechanism behind this vulnerability involves the maildrop utility's failure to properly drop group privileges when executing user-defined filter scripts. When maildrop runs with root privileges and encounters a .mailfilter file in a user's home directory, it maintains the root group identifier (gid) during script execution rather than switching to the appropriate user group context. This behavior creates a privilege escalation vector because malicious users can craft specially designed .mailfilter files that, when executed under root group privileges, can perform operations that would normally be restricted to privileged users. The vulnerability is classified under CWE-276 as improper privilege management, specifically involving inadequate group permissions handling.
The operational impact of this vulnerability is significant for systems running vulnerable versions of maildrop, particularly those where root access is required for mail processing operations. Local attackers with access to user accounts can exploit this flaw to execute arbitrary code with root privileges, potentially leading to complete system compromise. The attack requires minimal prerequisites since the vulnerability is triggered by normal mail processing operations, making it particularly dangerous in environments where maildrop is frequently used with elevated privileges. This weakness directly aligns with attack techniques documented in the ATT&CK framework under privilege escalation tactics, specifically leveraging misconfigured permissions and privilege management flaws.
Mitigation strategies for this vulnerability should focus on immediate patching of the maildrop utility to versions that properly handle group privileges during script execution. System administrators should ensure that maildrop is not run with root privileges when possible, and consider implementing additional security controls such as proper file permissions and access controls for .mailfilter files. The vulnerability demonstrates the importance of privilege separation principles and proper sandboxing of user-provided content, which are fundamental concepts in secure system design. Organizations should also implement monitoring for unauthorized changes to mail filtering configurations and maintain up-to-date security patches for all mail processing utilities to prevent similar privilege escalation scenarios.