CVE-2009-4834: lib.php in Zeroboard 4.1 pl7 allows remote attackers to execute arbitrary PHP code via a crafted parameter nam

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MEDIUM 6.8DOWNGRADE

CVE-2009-4834 is a medium-severity flaw (CVSS 6.8) affecting zeroboard. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

lib.php in Zeroboard 4.1 pl7 allows remote attackers to execute arbitrary PHP code via a crafted parameter name, possibly related to now_connect.php.

Why this priority

EPSS top 9%: very likely to be exploited
Public exploit reference

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

Risk facts

CVSS score	6.8 (Medium)
EPSS exploit chance	4.0% (top 9%)
CISA exploited list	No
Weakness	CWE-94
Published	2010-05-04
Last modified	2026-06-16

Publisher (CNA): MITRE · Vendor: xpressengine

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

Am I affected?

Timeline

2010-05-04 16:00 UTCPublished CVE record published
2026-06-16 23:14 UTCUpdated Record last modified

xpressengine zeroboard DOWNGRADE

Affected: 4.1 pl7

Fixed in: no fixed release known

Safe to downgrade to: a release before 4.1

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 4.1 (Debian / Ubuntu)

apt-cache madison zeroboard sudo apt install zeroboard=<VERSION_BEFORE_4.1> sudo apt-mark hold zeroboard

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

dnf --showduplicates list zeroboard sudo dnf downgrade zeroboard-<VERSION_BEFORE_4.1> sudo dnf versionlock add zeroboard

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: ZeroBoard 4.1 pl7 - 'now_connect()' Remote Code Execution

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-2009-4834?

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

Is CVE-2009-4834 being exploited?

CVE-2009-4834 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-2009-4834 affect?

CVE-2009-4834 affects zeroboard. Severity is medium (CVSS 6.8). lib.php in Zeroboard 4.1 pl7 allows remote attackers to execute arbitrary PHP code via a crafted parameter name, possibly related to now_connect.php.

How urgent is CVE-2009-4834?

Priority 51/100. EPSS top 9%: very likely to be exploited; Public exploit reference

Software pages

PHP vulnerabilities

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References

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