CyberRota Analysis
AI-GeneratedAuthenticated IMAP users can exploit a vulnerability in Courier IMAP versions prior to 6.0.1 and Courier Mail Server versions before 2.0.2 by sending deeply nested parenthesized SEARCH queries, leading to a stack overflow and crashing the imapd process. This issue arises from the lack of depth limits in the SEARCH command parser, which can be easily triggered due to the absence of a command line length restriction. Organizations using affected versions should prioritize patching to prevent potential denial-of-service attacks.
Public Exploit Signal
A public exploit, PoC, GitHub repository or Metasploit reference was detected for this CVE.
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Original NVD Description
Courier IMAP before 6.0.1 and Courier Mail Server before 2.0.2 allow authenticated IMAP users to crash the imapd process via deeply nested parenthesized SEARCH queries. The SEARCH command parser (alloc_search_key in searchinfo.C) recursively descends on nested parenthesized groups through a mutual recursion chain with alloc_search_andlist() and alloc_search_notkey(), with no depth limit. Courier IMAP has no overall command line length limit, making exploitation trivial. A single IMAP command with ~2500 nested parentheses overflows the 8MB default stack, causing SIGSEGV.