Courier IMAP < 6.0.1 Mail Server < 2.0.2 Stack Overflow DoS via Nested SEARCH Queries

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.

SQL injection vulnerability in authpgsqllib.c in Courier-Authlib before 0.62.0, when a non-Latin locale Postgres database is used, allows remote attackers to execute arbitrary SQL commands via query parameters containing apostrophes.

SQL injection vulnerability in the Courier Authentication Library (aka courier-authlib) before 0.60.6 on SUSE openSUSE 10.3 and 11.0, and other platforms, when MySQL and a non-Latin character set are used, allows remote attackers to execute arbitrary SQL commands via the username and unspecified other vectors.

An issue was discovered in the POP3 component of Courier Mail Server before 1.1.5. Meddler-in-the-middle attackers can pipeline commands after the POP3 STLS command, injecting plaintext commands into an encrypted user session.