What is CVE-2024-52596?

CVE-2024-52596 is a high-severity XML external entity injection (XXE) vulnerability in simplesamlphp/xml-common (composer), affecting versions < 1.20. It is fixed in 1.20.0. An XML parser processes external entity references in untrusted input, causing the server to fetch internal resources or remote URLs.

Which versions of simplesamlphp/xml-common are affected by CVE-2024-52596?

simplesamlphp/xml-common (composer) versions < 1.20 is affected.

Is there a fix for CVE-2024-52596?

Yes. CVE-2024-52596 is fixed in 1.20.0. Upgrade to this version or later.

Is CVE-2024-52596 exploitable, and should I be worried?

Whether CVE-2024-52596 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk.

What actually determines whether CVE-2024-52596 is exploitable, and how bad it is?

Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.

CVE-2024-52596 in simplesamlphp/xml-common

Q: Which versions of simplesamlphp/xml-common are affected by CVE-2024-52596?

simplesamlphp/xml-common (composer) versions < 1.20 is affected.

Q: Is there a fix for CVE-2024-52596?

Yes. CVE-2024-52596 is fixed in 1.20.0. Upgrade to this version or later.

Q: Is CVE-2024-52596 exploitable, and should I be worried?

Whether CVE-2024-52596 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk.

Q: What actually determines whether CVE-2024-52596 is exploitable, and how bad it is?

Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.

Q: How do I fix CVE-2024-52596?

Upgrade simplesamlphp/xml-common to 1.20.0 or later.

Summary

SimpleSAMLphp xml-common XXE vulnerability

When loading an (untrusted) XML document, for example the SAMLResponse, it's possible to induce an XXE.

$options is defined as: https://github.com/simplesamlphp/xml-common/blob/v1.19.0/src/DOMDocumentFactory.php#L39
including the DTDLoad option, which allows an attacker to read file contents from local file system OR internal network.

While there is the NONET option, an attacker can simply bypass if by using PHP filters:
php://filter/convert.base64-encode/resource=http://URL OR FILE

From there an attacker can induce network connections and steal the targeted file OOB (haven't fully tested this).

RCE may be possible with the php://expect or php://phar wrappers, but this hasn't been tested.

Note:
The mitigation here:
https://github.com/simplesamlphp/xml-common/blob/v1.19.0/src/DOMDocumentFactory.php#L58
Comes too late, as the XML has already been loaded into a document.
Mitigation:

Remove the LIBXML_DTDLOAD | LIBXML_DTDATTR options.
Additionally, as a defense in depth measure, check if there is the string: <!DOCTYPE inside the XML before parsing it. (This is not a complete fix because someone may be able to exploit some parser differentials, to load a DOCTYPE, maybe through spacing like: <! DOCTYPE)

Impact

An XML parser processes external entity references in untrusted input, causing the server to fetch internal resources or remote URLs. Typical impact: local file disclosure, server-side request forgery, or denial of service.

Affected versions

simplesamlphp/xml-common (< 1.20)

Security releases

simplesamlphp/xml-common → 1.20.0 (composer)

Kodem intelligence

Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.

Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.

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Remediation advice

Upgrade simplesamlphp/xml-common to 1.20.0 or later to resolve this vulnerability.

Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.

Frequently Asked Questions

What is CVE-2024-52596? CVE-2024-52596 is a high-severity XML external entity injection (XXE) vulnerability in simplesamlphp/xml-common (composer), affecting versions < 1.20. It is fixed in 1.20.0. An XML parser processes external entity references in untrusted input, causing the server to fetch internal resources or remote URLs.
Which versions of simplesamlphp/xml-common are affected by CVE-2024-52596? simplesamlphp/xml-common (composer) versions < 1.20 is affected.
Is there a fix for CVE-2024-52596? Yes. CVE-2024-52596 is fixed in 1.20.0. Upgrade to this version or later.
Is CVE-2024-52596 exploitable, and should I be worried? Whether CVE-2024-52596 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
What actually determines whether CVE-2024-52596 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
How do I fix CVE-2024-52596? Upgrade simplesamlphp/xml-common to 1.20.0 or later.