How severe is CVE-2007-4556?

No CVSS score has been assigned to CVE-2007-4556 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2007-4556?

CVE-2007-4556 affects the following packages: opensymphony:xwork (Maven), opensymphony:xwork (Maven). Ecosystems affected: Maven.

How do I fix CVE-2007-4556?

Update opensymphony:xwork to 1.2.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2007-4556 is resolved across your whole dependency graph.

How do I detect CVE-2007-4556 in my Maven dependencies?

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

How do I mitigate CVE-2007-4556 if there is no patch (or I can't update yet)?

Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.

Is CVE-2007-4556 actively exploited in the wild?

No public exploit code has been indexed for CVE-2007-4556 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2007-4556?

CVE-2007-4556 has an EPSS (Exploit Prediction Scoring System) score of 25.7%, placing it in the 98th 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 warrants monitoring and prompt remediation.

Is there exploit tooling available for CVE-2007-4556?

A Nuclei detection template exists for CVE-2007-4556, meaning automated scanners can fingerprint it. Public exploit tooling significantly increases real-world risk — prioritize patching and ensure detection coverage. Exploit tooling should only ever be used in isolated, authorized testing environments.

When was CVE-2007-4556 published, and has it been updated?

CVE-2007-4556 was published on May 1, 2022 and was last updated on November 30, 2024. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

CVE-2007-4556: xwork RCE — Fixed in 1.2.3

EPSS Exploitation Probability

via FIRST.org ↗

25.7%probability of exploitation in next 30 days

Moderate Risk0.00%

Lower risk than most CVEs98th percentile — riskier than 98% of all scored CVEsHighest risk

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

Real-World Exposure

2 pkgs affected

☕opensymphony:xwork☕opensymphony:xwork

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

Description

XWork is an command-pattern framework that is used to power WebWork as well as other applications. Struts support in OpenSymphony XWork before 1.2.3, and 2.x before 2.0.4, as used in WebWork and Apache Struts, recursively evaluates all input as an Object-Graph Navigation Language (OGNL) expression when altSyntax is enabled, which allows remote attackers to cause a denial of service (infinite loop) or execute arbitrary code via form input beginning with a "%{" sequence and ending with a "}" character.

Note: Version 2.0.4 marks the change from opensymphony:xwork to com.opensymphony:xwork.

Affected Packages

2 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
☕Maven	`opensymphony:xwork`	all versions	1.2.3`opensymphony:xwork:1.2.3`
☕Maven	`opensymphony:xwork`	≥ 2.0.0&&< 2.0.4	2.0.4`opensymphony:xwork:2.0.4`

Affected Products

1 product · 2 configurations

Application

xworkopensymphony

≥ 2.0.0 && ≤ 2.0.4

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for opensymphony:xwork, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update opensymphony:xwork to 1.2.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2007-4556 is resolved across your whole dependency graph.
Workarounds
Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.

How to detect CVE-2007-4556

A community-maintained Nuclei template exists for this CVE. You can scan for it directly:

nuclei -id cve-2007-4556 -u https://target

Template: OpenSymphony XWork/Apache Struts2 - Remote Code Execution
Severity: medium
Impact: Remote code execution
Remediation: Update to the latest version of Apache Struts2

Template by ProjectDiscovery nuclei-templates (pikpikcu), MIT licensed. View the full template. Scan only systems you are authorised to test.

Frequently Asked Questions

XWork is an command-pattern framework that is used to power WebWork as well as other applications. Struts support in OpenSymphony XWork before 1.2.3, and 2.x before 2.0.4, as used in WebWork and Apache Struts, recursively evaluates all input as an Object-Graph Navigation Language (OGNL) expression when altSyntax is enabled, which allows remote attackers to cause a denial of service (infinite loop) or execute arbitrary code via form input beginning with a "%{" sequence and ending with a "}" character. Note: Version 2.0.4 marks the change from `opensymphony:xwork` to `com.opensymphony:xwork`.

O3 Security · Impact-Aware SCA

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