CVE-2012-3867: lib/puppet/ssl/certificate_authority.rb in Puppet before 2.6.17 and 2.7.x before 2.7.18, and Puppet Enterprise

Q: How do I fix CVE-2012-3867?

puppet: downgrade or apply the listed mitigation; puppet: upgrade to newer than 2.6.16; debian linux: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Q: Is CVE-2012-3867 being exploited?

CVE-2012-3867 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-2012-3867 affect?

CVE-2012-3867 affects puppet, puppet, debian linux. Severity is medium (CVSS 4.3). lib/puppet/ssl/certificate_authority.rb in Puppet before 2.6.17 and 2.7.x before 2.7.18, and Puppet Enterprise before 2.5.2, does not properly restrict the characters in the Common Name field of a Certificate Signing Request (CSR), which ma

Q: How urgent is CVE-2012-3867?

Priority 46/100. Public exploit reference; On your watchlist

This month

MEDIUM 4.3WATCHLISTDOWNGRADEUPGRADEMITIGATE

CVE-2012-3867 is a medium-severity flaw (CVSS 4.3) affecting puppet, puppet, debian linux. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

lib/puppet/ssl/certificate_authority.rb in Puppet before 2.6.17 and 2.7.x before 2.7.18, and Puppet Enterprise before 2.5.2, does not properly restrict the characters in the Common Name field of a Certificate Signing Request (CSR), which makes it easier for user-assisted remote attackers to trick administrators into signing a crafted agent certificate via ANSI control sequences.

Why this priority

Public exploit reference
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	4.3 (Medium)
EPSS exploit chance	2.5% (top 16%)
CISA exploited list	No
Weakness	CWE-264
Published	2012-08-06
Last modified	2026-06-16

Publisher (CNA): MITRE · Vendor: canonical · debian · opensuse · puppet · puppetlabs · suse

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

Am I affected?

Timeline

2012-08-06 16:55 UTCPublished CVE record published
2026-06-16 23:44 UTCUpdated Record last modified

puppet puppet DOWNGRADE

Affected: 2.6.0 · 2.6.1 · 2.6.2 · 2.6.3 · 2.6.4 · 2.6.5 · 2.6.6 · 2.6.7

Fixed in: no fixed release known

Safe to downgrade to: a release before 2.6.0

1. Check installed version

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

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

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

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

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

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.

puppetlabs puppet UPGRADE

Affected: <= 2.6.16 · 2.7.0 · 2.7.1

Fixed in: newer than 2.6.16

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to newer than 2.6.16 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade puppet

Note

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

debian debian linux MITIGATE

Affected: 6.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 6.0

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.

canonical ubuntu linux MITIGATE

Affected: 10.04 · 11.04 · 11.10 · 12.04

Fixed in: no fixed release known

Safe to downgrade to: a release before 10.04

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.

opensuse opensuse MITIGATE

Affected: 11.4 · 12.1

Fixed in: no fixed release known

Safe to downgrade to: a release before 11.4

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.

suse linux enterprise desktop MITIGATE

Affected: 11 sp1 · 11 sp2

Fixed in: no fixed release known

Safe to downgrade to: a release before 11

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-2012-3867?

puppet: downgrade or apply the listed mitigation; puppet: upgrade to newer than 2.6.16; debian linux: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2012-3867 being exploited?

CVE-2012-3867 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-2012-3867 affect?

CVE-2012-3867 affects puppet, puppet, debian linux. Severity is medium (CVSS 4.3). lib/puppet/ssl/certificate_authority.rb in Puppet before 2.6.17 and 2.7.x before 2.7.18, and Puppet Enterprise before 2.5.2, does not properly restrict the characters in the Common Name field of a Certificate Signing Request (CSR), which ma

How urgent is CVE-2012-3867?

Priority 46/100. Public exploit reference; On your watchlist

Software pages

Ubuntu vulnerabilities · Debian vulnerabilities

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References

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