How severe is CVE-2015-5243?

CVE-2015-5243 has a CVSS score of 9.8/10, rated CRITICAL. Immediate patching is strongly recommended.

Which packages are affected by CVE-2015-5243?

CVE-2015-5243 affects the following packages: jsmitty12/phpwhois (Packagist), phpwhois/phpwhois (Packagist), brightlocal/phpwhois (Packagist), david-garcia/phpwhois (Packagist), ivankristianto/phpwhois (Packagist), kazist/phpwhois (Packagist), serluck/phpwhois (Packagist), simple-updates/phpwhois (Packagist), and 1 more. Ecosystems affected: Packagist.

How do I fix CVE-2015-5243?

Update jsmitty12/phpwhois to 5.1.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2015-5243 is resolved across your whole dependency graph.

How do I detect CVE-2015-5243 in my Packagist dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for jsmitty12/phpwhois, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2015-5243 if there is no patch (or I can't update yet)?

Stop passing untrusted input into the interpreter or shell: call the affected binary with an argument array rather than a composed command string, reject anything outside a strict allowlist of expected values, and run the component under an account that cannot reach beyond the work it legitimately does.

Is CVE-2015-5243 actively exploited in the wild?

Yes. There are 1 known exploit references for CVE-2015-5243, including 1 in-the-wild exploitation observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2015-5243?

CVE-2015-5243 has an EPSS (Exploit Prediction Scoring System) score of 6.2%, placing it in the 94th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2015-5243?

CVE-2015-5243 is classified as Code Injection (CWE-94). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was CVE-2015-5243 published, and has it been updated?

CVE-2015-5243 was published on May 14, 2022 and was last updated on April 23, 2024. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐘

🐘 Packagist

Not in CISA KEV

CRITICAL severity

CVE-2015-5243 — phpwhois

CRITICALFix: Gemorroj/phpwhois@91c937e

CVE-2015-5243 is a critical-severity (CVSS 9.8) Code Injection vulnerability in jsmitty12/phpwhois. 1 public exploit or proof-of-concept reference is indexed, so weaponization risk is real. A fix is available for jsmitty12/phpwhois — see the affected versions and patch details below.

phpWhois arbitrary code execution via a crafted whois record

Published

May 14, 2022

Updated

Apr 23, 2024

Affected

9 pkgs

Patched

1 / 9

Exploits

1 known

Exploitation data as of Nov 6, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

6.2%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs94th percentile — riskier than 94% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

9 pkgs affected

🐘jsmitty12/phpwhois🐘phpwhois/phpwhois🐘brightlocal/phpwhois🐘david-garcia/phpwhois🐘ivankristianto/phpwhois🐘kazist/phpwhois🐘serluck/phpwhois🐘simple-updates/phpwhois+1 more

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.

Description

phpWhois allows remote attackers to execute arbitrary code via a crafted whois record.

Affected Packages

9 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐘Packagist	`jsmitty12/phpwhois`	all versions	5.1.0`composer require jsmitty12/phpwhois:^5.1.0`
🐘Packagist	`phpwhois/phpwhois`	all versions	No fix
🐘Packagist	`brightlocal/phpwhois`	all versions	No fix
🐘Packagist	`david-garcia/phpwhois`	all versions	No fix
🐘Packagist	`ivankristianto/phpwhois`	all versions	No fix
🐘Packagist	`kazist/phpwhois`	all versions	No fix

Affected Products

1 product · 1 configurations

Application

phpwhoisphpwhois_project

≤ 4.2.2

range

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

phpWhois allows remote attackers to execute arbitrary code via a crafted…

github.comNVDJun 2019

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for jsmitty12/phpwhois, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update jsmitty12/phpwhois to 5.1.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2015-5243 is resolved across your whole dependency graph.
Workarounds
Stop passing untrusted input into the interpreter or shell: call the affected binary with an argument array rather than a composed command string, reject anything outside a strict allowlist of expected values, and run the component under an account that cannot reach beyond the work it legitimately does.

Frequently Asked Questions

phpWhois allows remote attackers to execute arbitrary code via a crafted whois record.

O3 Security · Impact-Aware SCA

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