fetchmail not enforcing TLS for POP3 properly

fetchmail before 6.3.6-rc4 does not properly enforce TLS and may transmit cleartext passwords over unsecured links if certain circumstances occur, which allows remote attackers to obtain sensitive information via man-in-the-middle (MITM) attacks.

fetchmail 6.3.5 and 6.3.6 before 6.3.6-rc4, when refusing a message delivered via the mda option, allows remote attackers to cause a denial of service (crash) via unknown vectors that trigger a NULL pointer dereference when calling the (1) ferror or (2) fflush functions.

Fetchmail NULL pointer dereference

sink.c in fetchmail before 6.3.9 allows context-dependent attackers to cause a denial of service (NULL dereference and application crash) by refusing certain warning messages that are sent over SMTP.

fetchmail: Crash in large log messages in verbose mode

fetchmail 6.3.8 and earlier, when running in -v -v (aka verbose) mode, allows remote attackers to cause a denial of service (crash and persistent mail failure) via a malformed mail message with long headers, which triggers an erroneous dereference when using vsnprintf to format log messages.

fetchmail: SSL null terminator bypass

socket.c in fetchmail before 6.3.11 does not properly handle a '\0' character in a domain name in the subject's Common Name (CN) field of an X.509 certificate, which allows man-in-the-middle attackers to spoof arbitrary SSL servers via a crafted certificate issued by a legitimate Certification Authority, a related issue to CVE-2009-2408.

security flaw

Buffer overflows in Fetchmail 6.0.0 and earlier allow remote attackers to cause a denial of service (crash) or execute arbitrary code via (1) long headers that are not properly processed by the readheaders function, or (2) via long Received: headers, which are not properly parsed by the parse_received function.

security flaw

The getmxrecord function in Fetchmail 6.0.0 and earlier does not properly check the boundary of a particular malformed DNS packet from a malicious DNS server, which allows remote attackers to cause a denial of service (crash) when Fetchmail attempts to read data beyond the expected boundary.

security flaw

Heap-based buffer overflow in Fetchmail 6.1.3 and earlier does not account for the "@" character when determining buffer lengths for local addresses, which allows remote attackers to execute arbitrary code via a header with a large number of local addresses.

security flaw

Fetchmail 6.2.4 and earlier does not properly allocate memory for long lines, which allows remote attackers to cause a denial of service (crash) via a certain email.

security flaw

Buffer overflow in the POP3 client in Fetchmail before 6.2.5.2 allows remote POP3 servers to cause a denial of service and possibly execute arbitrary code via long UIDL responses. NOTE: a typo in an advisory accidentally used the wrong CVE identifier for the Fetchmail issue. This is the correct identifier.

security flaw

fetchmailconf before 1.49 in fetchmail 6.2.0, 6.2.5 and 6.2.5.2 creates configuration files with insecure world-readable permissions, which allows local users to obtain sensitive information such as passwords.

security flaw

fetchmail before 6.3.1 and before 6.2.5.5, when configured for multidrop mode, allows remote attackers to cause a denial of service (application crash) by sending messages without headers from upstream mail servers.

fetchmail 6.3.0 and other versions before 6.3.2 allows remote attackers to cause a denial of service (crash) via crafted e-mail messages that cause a free of an invalid pointer when fetchmail bounces the message to the originator or local postmaster.

security flaw

Vulnerability in fetchmail 5.5.0-2 and earlier in the AUTHENTICATE GSSAPI command.

security flaw

A buffer overflow in Linux fetchmail before 5.8.6 allows remote attackers to execute arbitrary code via a large 'To:' field in an email header.

security flaw

Fetchmail (aka fetchmail-ssl) before 5.8.17 allows a remote malicious (1) IMAP server or (2) POP/POP3 server to overwrite arbitrary memory and possibly gain privileges via a negative index number as part of a response to a LIST request.

security flaw

fetchmailconf in fetchmail before 5.7.4 allows local users to overwrite files of other users via a symlink attack on temporary files.

security flaw

fetchmail email client before 5.9.10 does not properly limit the maximum number of messages available, which allows a remote IMAP server to overwrite memory via a message count that exceeds the boundaries of an array.

fetchmail: Fetchmail denial of service

In fetchmail before 6.5.6, the SMTP client can crash when authenticating upon receiving a 334 status code in a malformed context.

fetchmail: denial of service in debug mode with multichar locales

fetchmail 4.6.3 through 6.3.16, when debug mode is enabled, does not properly handle invalid characters in a multi-character locale, which allows remote attackers to cause a denial of service (memory consumption and application crash) via a crafted (1) message header or (2) POP3 UIDL list.