PatchTheCVECVE-2003-0694: The prescan function in Sendmail 8.12.9 allows remote attackers to execute arbitrary code via buffer overflow
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HIGH 10.0DOWNGRADEDOWNGRADEDOWNGRADE
CVE-2003-0694 is a high-severity flaw (CVSS 10.0) affecting advanced message server, sendmail, sendmail pro. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
The prescan function in Sendmail 8.12.9 allows remote attackers to execute arbitrary code via buffer overflow attacks, as demonstrated using the parseaddr function in parseaddr.c.
Why this priority
- Critical severity
- EPSS top 1%: very likely to be exploited
- Public exploit reference
No fix is published yet: follow the downgrade or mitigation steps.
Risk facts
| CVSS score | 10.0 (High) |
| EPSS exploit chance | 66.2% (top 1%) |
| CISA exploited list | No |
| Published | 2003-10-06 |
| Last modified | 2026-06-16 |
Last updated 2026-06-16 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
sendmail advanced message server DOWNGRADE
Affected: 1.2 · 1.3
Fixed in: no fixed release known
Safe to downgrade to: a release before 1.2
1. Check installed version
apt-cache policy advanced-message-server || rpm -q advanced-message-server || advanced-message-server --version
2. No fixed release: DOWNGRADE to a release before 1.2 (Debian / Ubuntu)
apt-cache madison advanced-message-server
sudo apt install advanced-message-server=<VERSION_BEFORE_1.2>
sudo apt-mark hold advanced-message-server
2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)
dnf --showduplicates list advanced-message-server
sudo dnf downgrade advanced-message-server-<VERSION_BEFORE_1.2>
sudo dnf versionlock add advanced-message-server
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.
sendmail sendmail DOWNGRADE
Affected: 2.6 · 2.6.1 · 2.6.2 · 3.0 · 3.0.1 · 3.0.2 · 3.0.3 · 8.8.8
Fixed in: no fixed release known
Safe to downgrade to: a release before 2.6
1. Check installed version
apt-cache policy sendmail || rpm -q sendmail || sendmail --version
2. No fixed release: DOWNGRADE to a release before 2.6 (Debian / Ubuntu)
apt-cache madison sendmail
sudo apt install sendmail=<VERSION_BEFORE_2.6>
sudo apt-mark hold sendmail
2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)
dnf --showduplicates list sendmail
sudo dnf downgrade sendmail-<VERSION_BEFORE_2.6>
sudo dnf versionlock add sendmail
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.
sendmail sendmail pro DOWNGRADE
Affected: 8.9.2 · 8.9.3
Fixed in: no fixed release known
Safe to downgrade to: a release before 8.9.2
1. Check installed version
apt-cache policy sendmail-pro || rpm -q sendmail-pro || sendmail-pro --version
2. No fixed release: DOWNGRADE to a release before 8.9.2 (Debian / Ubuntu)
apt-cache madison sendmail-pro
sudo apt install sendmail-pro=<VERSION_BEFORE_8.9.2>
sudo apt-mark hold sendmail-pro
2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)
dnf --showduplicates list sendmail-pro
sudo dnf downgrade sendmail-pro-<VERSION_BEFORE_8.9.2>
sudo dnf versionlock add sendmail-pro
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.
sendmail sendmail switch DOWNGRADE
Affected: 2.1 · 2.1.1 · 2.1.2 · 2.1.3 · 2.1.4 · 2.1.5 · 2.2 · 2.2.1
Fixed in: no fixed release known
Safe to downgrade to: a release before 2.1
1. Check installed version
apt-cache policy sendmail-switch || rpm -q sendmail-switch || sendmail-switch --version
2. No fixed release: DOWNGRADE to a release before 2.1 (Debian / Ubuntu)
apt-cache madison sendmail-switch
sudo apt install sendmail-switch=<VERSION_BEFORE_2.1>
sudo apt-mark hold sendmail-switch
2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)
dnf --showduplicates list sendmail-switch
sudo dnf downgrade sendmail-switch-<VERSION_BEFORE_2.1>
sudo dnf versionlock add sendmail-switch
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.
sgi irix MITIGATE
Affected: 6.5.15 · 6.5.16 · 6.5.17f · 6.5.17m · 6.5.18f · 6.5.18m · 6.5.19f · 6.5.19m
Fixed in: no fixed release known
Safe to downgrade to: a release before 6.5.15
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.
apple mac os x MITIGATE
Affected: 10.2 · 10.2.1 · 10.2.2 · 10.2.3 · 10.2.4 · 10.2.5 · 10.2.6
Fixed in: no fixed release known
Safe to downgrade to: a release before 10.2
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.
Public exploits and detection
Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.
- Metasploit: Sendmail SMTP Address prescan Memory Corruption
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.
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-2003-0694?
advanced message server: downgrade or apply the listed mitigation; sendmail: downgrade or apply the listed mitigation; sendmail pro: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.
Is CVE-2003-0694 being exploited?
CVE-2003-0694 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-2003-0694 affect?
CVE-2003-0694 affects advanced message server, sendmail, sendmail pro. Severity is high (CVSS 10.0). The prescan function in Sendmail 8.12.9 allows remote attackers to execute arbitrary code via buffer overflow attacks, as demonstrated using the parseaddr function in parseaddr.c.
How urgent is CVE-2003-0694?
Priority 65/100. Critical severity; EPSS top 1%: very likely to be exploited; Public exploit reference
Related CVEs
- CVE-2003-0681 HIGH 7.5 DOWNGRADE DOWNGRADE A "potential buffer overflow in ruleset parsing" for Sendmail 8.12.9, when using the nonstandard rulesets (1)