CVE-2009-0770: dkim-milter 2.6.0 through 2.8.0 allows remote attackers to cause a denial of service (crash) by signing a mess

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MEDIUM 5.0DOWNGRADE

CVE-2009-0770 is a medium-severity flaw (CVSS 5.0) affecting dkim-milter. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

dkim-milter 2.6.0 through 2.8.0 allows remote attackers to cause a denial of service (crash) by signing a message with a key that has been revoked in DNS, which triggers an assertion error.

Why this priority

Public exploit reference

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

Risk facts

CVSS score	5.0 (Medium)
EPSS exploit chance	2.8% (top 14%)
CISA exploited list	No
Published	2009-03-06
Last modified	2026-06-16

Publisher (CNA): MITRE · Vendor: dkim

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

Am I affected?

Timeline

2009-03-06 06:50 UTCPublished CVE record published
2026-06-16 23:05 UTCUpdated Record last modified

dkim dkim-milter DOWNGRADE

Affected: 2.6.0 · 2.7.0 · 2.7.1 · 2.7.2 · 2.8.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 2.6.0

1. Check installed version

apt-cache policy dkim-milter || rpm -q dkim-milter || dkim-milter --version

2. No fixed release: DOWNGRADE to a release before 2.6.0 (Debian / Ubuntu)

apt-cache madison dkim-milter sudo apt install dkim-milter=<VERSION_BEFORE_2.6.0> sudo apt-mark hold dkim-milter

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

dnf --showduplicates list dkim-milter sudo dnf downgrade dkim-milter-<VERSION_BEFORE_2.6.0> sudo dnf versionlock add dkim-milter

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.

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-2009-0770?

dkim-milter: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2009-0770 being exploited?

CVE-2009-0770 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-2009-0770 affect?

CVE-2009-0770 affects dkim-milter. Severity is medium (CVSS 5.0). dkim-milter 2.6.0 through 2.8.0 allows remote attackers to cause a denial of service (crash) by signing a message with a key that has been revoked in DNS, which triggers an assertion error.

How urgent is CVE-2009-0770?

Priority 44/100. Public exploit reference

References

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