CVE-2018-12268: acccheck.pl in acccheck 0.2.1 allows Command Injection via shell metacharacters in a username or password file

This week

CRITICAL 9.8REMOTEDOWNGRADE

CVE-2018-12268 is a critical-severity flaw (CVSS 9.8) affecting acccheck.pl. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

acccheck.pl in acccheck 0.2.1 allows Command Injection via shell metacharacters in a username or password file, as demonstrated by injection into an smbclient command line.

Why this priority

Critical severity
Public exploit reference
Remotely exploitable, no login, no user action

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

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	2.6% (top 15%)
CISA exploited list	No
Weakness	CWE-78
Published	2018-06-13
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: acccheck project

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2018-06-13 11:29 UTCPublished CVE record published
2026-06-17 01:37 UTCUpdated Record last modified

acccheck project acccheck.pl DOWNGRADE

Affected: 0.2.1

Fixed in: no fixed release known

Safe to downgrade to: a release before 0.2.1

1. Check installed version

apt-cache policy acccheck.pl || rpm -q acccheck.pl || acccheck.pl --version

2. No fixed release: DOWNGRADE to a release before 0.2.1 (Debian / Ubuntu)

apt-cache madison acccheck.pl sudo apt install acccheck.pl=<VERSION_BEFORE_0.2.1> sudo apt-mark hold acccheck.pl

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

dnf --showduplicates list acccheck.pl sudo dnf downgrade acccheck.pl-<VERSION_BEFORE_0.2.1> sudo dnf versionlock add acccheck.pl

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-2018-12268?

acccheck.pl: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2018-12268 being exploited?

CVE-2018-12268 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-2018-12268 affect?

CVE-2018-12268 affects acccheck.pl. Severity is critical (CVSS 9.8). acccheck.pl in acccheck 0.2.1 allows Command Injection via shell metacharacters in a username or password file, as demonstrated by injection into an smbclient command line.

How urgent is CVE-2018-12268?

Priority 66/100. Critical severity; Public exploit reference; Remotely exploitable, no login, no user action

References

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