CVE-2003-0540: Medium severity wietse venema postfix vulnerability
The address parser code in Postfix 1.1.12 and earlier allows remote attackers to cause a denial of service (lock) via (1) a malformed envelope address to a local host that would generate a bounce and contains the ".!" string in the MAIL FROM or Errors-To headers, which causes nqmgr to lock up, or (2) via a valid MAIL FROM with a RCPT TO containing a ".!" string, which causes an instance of the SMTP listener to lock up.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Compensating control
At the network perimeter or SMTP gateway, filter or drop SMTP traffic that contains the substring ".!" in envelope addresses (MAIL FROM or RCPT TO) or in Errors-To headers to prevent triggering the Postfix address parser bug.
- Operational
Inventory Postfix installations and identify any running version "1.1.12" or earlier. For any hosts running Postfix 1.1.12 or earlier, stop or disable the Postfix service (for example, 'service postfix stop' or 'systemctl stop postfix') and/or isolate the host from the network until a vendor fix is available.
Event History
Frequently Asked Questions
What is the severity of CVE-2003-0540?
CVE-2003-0540 has a severity rating that indicates it can lead to a denial of service condition.
How do I fix CVE-2003-0540?
To fix CVE-2003-0540, upgrade Postfix to version 1.1.13 or later.
What versions of Postfix are affected by CVE-2003-0540?
Postfix versions 1.1.12 and earlier are affected by CVE-2003-0540.
Can CVE-2003-0540 be exploited remotely?
Yes, CVE-2003-0540 can be exploited remotely through malformed envelope addresses.
What symptoms indicate an exploitation of CVE-2003-0540?
Symptoms include unexpected locking of the nqmgr process within the Postfix mail server.