CVE-2001-0690: Format string vulnerability in exim (3.22-10 in Red Hat, 3.12 in Debian and 3.16 in Conectiva) in batched SMTP

Q: How do I fix CVE-2001-0690?

exim: upgrade to newer than 3.22; linux: mitigate or apply the listed mitigation; debian linux: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Q: Is CVE-2001-0690 being exploited?

CVE-2001-0690 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2001-0690 affect?

CVE-2001-0690 affects exim, linux, debian linux. Severity is high (CVSS 7.5). Format string vulnerability in exim (3.22-10 in Red Hat, 3.12 in Debian and 3.16 in Conectiva) in batched SMTP mode allows a remote attacker to execute arbitrary code via format strings in SMTP mail headers.

Q: How urgent is CVE-2001-0690?

Priority 60/100. High severity; EPSS top 4%: very likely to be exploited; Public exploit reference; On your watchlist

This week

HIGH 7.5WATCHLISTUPGRADEMITIGATEMITIGATE

CVE-2001-0690 is a high-severity flaw (CVSS 7.5) affecting exim, linux, debian linux. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Format string vulnerability in exim (3.22-10 in Red Hat, 3.12 in Debian and 3.16 in Conectiva) in batched SMTP mode allows a remote attacker to execute arbitrary code via format strings in SMTP mail headers.

Why this priority

High severity
EPSS top 4%: very likely to be exploited
Public exploit reference
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	7.5 (High)
EPSS exploit chance	11.9% (top 4%)
CISA exploited list	No
Published	2001-09-20
Last modified	2026-06-16

Publisher (CNA): MITRE · Vendor: conectiva · debian · redhat · university of cambridge

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

Am I affected?

Timeline

2001-09-20 04:00 UTCPublished CVE record published
2026-06-16 21:54 UTCUpdated Record last modified

university of cambridge exim UPGRADE

Affected: <= 3.22

Fixed in: newer than 3.22

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to newer than 3.22 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade exim

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade exim

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

conectiva linux MITIGATE

Affected: all versions

Fixed in: no fixed release known

Safe to downgrade to: no unaffected older release

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.

debian debian linux MITIGATE

Affected: 4.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 4.0

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.

redhat linux MITIGATE

Affected: all versions

Fixed in: no fixed release known

Safe to downgrade to: no unaffected older release

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.

Exploit-DB: Exim 3.x - Format String

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-2001-0690?

exim: upgrade to newer than 3.22; linux: mitigate or apply the listed mitigation; debian linux: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2001-0690 being exploited?

CVE-2001-0690 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-2001-0690 affect?

CVE-2001-0690 affects exim, linux, debian linux. Severity is high (CVSS 7.5). Format string vulnerability in exim (3.22-10 in Red Hat, 3.12 in Debian and 3.16 in Conectiva) in batched SMTP mode allows a remote attacker to execute arbitrary code via format strings in SMTP mail headers.

How urgent is CVE-2001-0690?

Priority 60/100. High severity; EPSS top 4%: very likely to be exploited; Public exploit reference; On your watchlist

Software pages

Debian vulnerabilities · Exim vulnerabilities

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References

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