Description: mu-b has reported multiple vulnerabilities in eXtremail, which can be exploited by malicious people to cause a DoS (Denial of Service) or to potentially compromise a vulnerable system.
1) An integer underflow error exists within the processing of the POP3 "USER" command. This can be exploited to crash an affected server or potentially execute arbitrary code.
2) A boundary error exists within the processing of "LOGIN" commands sent to the administrative interface. This can be exploited to cause a stack-based buffer overflow by sending an overly long parameter with the affected command.
3) A boundary error exists within the processing of CRAM-MD5 authentication messages. This can be exploited to cause a heap-based buffer overflow.
4) A boundary error exists within the processing of the IMAP "AUTHENTICATE PLAIN" command. This can be exploited to cause a stack-based buffer overflow.
5) A boundary error exists within the processing of network packets. This can be exploited to cause a heap-based buffer overflow by sending specially crafted packets containing zero bytes to the IMAP port.
Successful exploitation of these vulnerabilities may allow execution of arbitrary code.
The vulnerabilities are reported in version 2.1.1. Other versions may also be affected.
Solution: Restrict network access to the affected server.
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