CVE-2011-4813: Directory traversal vulnerability in clientarea.php in WHMCompleteSolution (WHMCS) 3.x.x allows remote attacke

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MEDIUM 5.0DOWNGRADE

CVE-2011-4813 is a medium-severity flaw (CVSS 5.0) affecting whmcompletesolution. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Directory traversal vulnerability in clientarea.php in WHMCompleteSolution (WHMCS) 3.x.x allows remote attackers to read arbitrary files via an invalid action and a ../ (dot dot slash) in the templatefile parameter.

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	2.9% (top 13%)
CISA exploited list	No
Weakness	CWE-22
Published	2011-12-14
Last modified	2026-06-16

Publisher (CNA): MITRE · Vendor: whmcs

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

Am I affected?

Timeline

2011-12-14 00:55 UTCPublished CVE record published
2026-06-16 23:35 UTCUpdated Record last modified

whmcs whmcompletesolution DOWNGRADE

Affected: 3.0.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 3.0.0

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 3.0.0 (Debian / Ubuntu)

apt-cache madison whmcompletesolution sudo apt install whmcompletesolution=<VERSION_BEFORE_3.0.0> sudo apt-mark hold whmcompletesolution

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

dnf --showduplicates list whmcompletesolution sudo dnf downgrade whmcompletesolution-<VERSION_BEFORE_3.0.0> sudo dnf versionlock add whmcompletesolution

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.

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: WHMCompleteSolution (WHMCS) 3.x - 'clientarea.php' Local File Disclosure

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-2011-4813?

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

Is CVE-2011-4813 being exploited?

CVE-2011-4813 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-2011-4813 affect?

CVE-2011-4813 affects whmcompletesolution. Severity is medium (CVSS 5.0). Directory traversal vulnerability in clientarea.php in WHMCompleteSolution (WHMCS) 3.x.x allows remote attackers to read arbitrary files via an invalid action and a ../ (dot dot slash) in the templatefile parameter.

How urgent is CVE-2011-4813?

Priority 44/100. Public exploit reference

Software pages

PHP vulnerabilities

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References

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