How severe is CVE-2011-4340?

No CVSS score has been assigned to CVE-2011-4340 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2011-4340?

CVE-2011-4340 affects the following packages: symphonycms/symphony-2 (Packagist). Ecosystems affected: Packagist.

How do I fix CVE-2011-4340?

Update symphonycms/symphony-2 to 2.2.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2011-4340 is resolved across your whole dependency graph.

How do I detect CVE-2011-4340 in my Packagist dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for symphonycms/symphony-2, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2011-4340 if there is no patch (or I can't update yet)?

Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.

Is CVE-2011-4340 actively exploited in the wild?

Yes. There are 1 known exploit references for CVE-2011-4340, including 1 documented proof-of-concept exploit on Exploit-DB. 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-2011-4340?

CVE-2011-4340 has an EPSS (Exploit Prediction Scoring System) score of 1.8%, placing it in the 79th 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-2011-4340?

CVE-2011-4340 is classified as Cross-site Scripting (XSS) (CWE-79). 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-2011-4340 published, and has it been updated?

CVE-2011-4340 was published on May 17, 2022 and was last updated on April 12, 2025. 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

CVE-2011-4340 — symphony-2

CVE-2011-4340 is a Cross-site Scripting (XSS) vulnerability in symphonycms/symphony-2. 1 public exploit or proof-of-concept reference is indexed, so weaponization risk is real. A fix is available for symphonycms/symphony-2 — see the affected versions and patch details below.

Symphony CMS vulnerable to Cross-site Scripting

Published

May 17, 2022

Updated

Apr 12, 2025

Affected

1 pkg

Patched

1 / 1

Exploits

1 known

Exploitation data as of Nov 7, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

1.8%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs79th percentile — riskier than 79% of all scored CVEsHighest risk

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

Real-World Exposure

1 pkg affected

🐘symphonycms/symphony-2

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

Multiple cross-site scripting (XSS) vulnerabilities in Symphony CMS 2.2.3 and possibly other versions before 2.2.4 allow remote authenticated users with Author privileges to inject arbitrary web script or HTML via (1) the profile parameter to extensions/profiledevkit/content/content.profile.php, as demonstrated via requests to (a) the default URI, (b) about/, or (c) drafts/; or (2) the filter parameter in symphony/lib/core/class.symphony.php, as demonstrated via requests to (d) symphony/publish/comments or (e) symphony/publish/images. NOTE: some of these details are obtained from third party information.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐘Packagist	`symphonycms/symphony-2`	all versions	2.2.4`composer require symphonycms/symphony-2:^2.2.4`

Affected Products

1 product · 1 configurations

Application

symphony cmssymphony-cms

1 version

2.2.3

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.

EDB-36280webappsphp✓ Verified

Symphony 2.2.3 - '/symphony/publish/images?filter' Cross-Site Scripting

by Mesut Timur · Nov 1, 2011

Exploit-DB Source

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for symphonycms/symphony-2, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update symphonycms/symphony-2 to 2.2.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2011-4340 is resolved across your whole dependency graph.
Workarounds
Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.