Dovecot before version 2.2.29 is vulnerable to a denial of service. When 'dict' passdb and userdb were used for user authentication, the username sent by the IMAP/POP3 client was sent through var_expand() to perform %variable expansion. Sending specially crafted %variable fields could result in excessive memory usage causing the process to crash (and restart), or excessive CPU usage causing all authentications to hang.
{
"binaries": [
{
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"binary_version": "1:2.2.9-1ubuntu2.1"
},
{
"binary_name": "dovecot-dbg",
"binary_version": "1:2.2.9-1ubuntu2.1"
},
{
"binary_name": "dovecot-dev",
"binary_version": "1:2.2.9-1ubuntu2.1"
},
{
"binary_name": "dovecot-gssapi",
"binary_version": "1:2.2.9-1ubuntu2.1"
},
{
"binary_name": "dovecot-imapd",
"binary_version": "1:2.2.9-1ubuntu2.1"
},
{
"binary_name": "dovecot-ldap",
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},
{
"binary_name": "dovecot-lmtpd",
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},
{
"binary_name": "dovecot-managesieved",
"binary_version": "1:2.2.9-1ubuntu2.1"
},
{
"binary_name": "dovecot-mysql",
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},
{
"binary_name": "dovecot-pgsql",
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},
{
"binary_name": "dovecot-pop3d",
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},
{
"binary_name": "dovecot-sieve",
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},
{
"binary_name": "dovecot-solr",
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},
{
"binary_name": "dovecot-sqlite",
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},
{
"binary_name": "mail-stack-delivery",
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}
],
"availability": "No subscription required"
}