CVE-2003-0468: Postfix 1.1.11 and earlier allows remote attackers to use Postfix to conduct "bounce scans" or DDos attacks of

This month

MEDIUM 5.0WATCHLISTDOWNGRADEMITIGATE

CVE-2003-0468 is a medium-severity flaw (CVSS 5.0) affecting postfix, linux. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Postfix 1.1.11 and earlier allows remote attackers to use Postfix to conduct "bounce scans" or DDos attacks of other hosts via an email address to the local host containing the target IP address and service name followed by a "!" string, which causes Postfix to attempt to use SMTP to communicate with the target on the associated port.

Why this priority

On your watchlist

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	5.0 (Medium)
EPSS exploit chance	2.4% (top 16%)
CISA exploited list	No
Published	2003-08-27
Last modified	2026-06-16

Publisher (CNA): MITRE · Vendor: conectiva · wietse venema

Last updated 2026-06-16 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2003-08-27 04:00 UTCPublished CVE record published
2026-06-16 22:02 UTCUpdated Record last modified

wietse venema postfix DOWNGRADE

Affected: 1.0.21 · 1.1.11 · 1999-09-06 · 1999-12-31 · 2000-02-28 · 2001-11-15

Fixed in: no fixed release known

Safe to downgrade to: a release before 1.0.21

1. Check installed version

apt-cache policy postfix || rpm -q postfix || postfix --version

2. No fixed release: DOWNGRADE to a release before 1.0.21 (Debian / Ubuntu)

apt-cache madison postfix sudo apt install postfix=<VERSION_BEFORE_1.0.21> sudo apt-mark hold postfix

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list postfix sudo dnf downgrade postfix-<VERSION_BEFORE_1.0.21> sudo dnf versionlock add postfix

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

conectiva linux MITIGATE

Affected: 7.0 · 8.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 7.0

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2003-0468?

postfix: downgrade or apply the listed mitigation; linux: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2003-0468 being exploited?

CVE-2003-0468 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2003-0468 affect?

CVE-2003-0468 affects postfix, linux. Severity is medium (CVSS 5.0). Postfix 1.1.11 and earlier allows remote attackers to use Postfix to conduct "bounce scans" or DDos attacks of other hosts via an email address to the local host containing the target IP address and service name followed by a "!" string, wh

How urgent is CVE-2003-0468?

Priority 43/100. On your watchlist

Software pages

Postfix vulnerabilities

Related CVEs

CVE-2023-51764 MEDIUM 5.3 UPGRADE MITIGATE Postfix through 3.8.5 allows SMTP smuggling unless configured with smtpd_data_restrictions=reject_unauth_pipel
CVE-2026-43964 LOW 3.7 UPGRADE Postfix before 3.8.16, 3.9 before 3.9.10, and 3.10 before 3.10.9 sometimes allows a buffer over-read and proce
CVE-2020-12063 MEDIUM 5.3 DOWNGRADE A certain Postfix 2.10.1-7 package could allow an attacker to send an email from an arbitrary-looking sender v
CVE-2017-10140 HIGH 7.8 UPGRADE Postfix before 2.11.10, 3.0.x before 3.0.10, 3.1.x before 3.1.6, and 3.2.x before 3.2.2 might allow local user
CVE-2012-0811 MEDIUM 6.5 UPGRADE Multiple SQL injection vulnerabilities in Postfix Admin (aka postfixadmin) before 2.3.5 allow remote authentic

References

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