Summary
php-svg-lib lacks path validation on font through SVG inline styles
php-svg-lib fails to validate that font-family doesn't contain a PHAR url, which might leads to RCE on PHP < 8.0, and doesn't validate if external references are allowed. This might leads to bypass of restrictions or RCE on projects that are using it, if they do not strictly revalidate the fontName that is passed by php-svg-lib.
Details
The Style::fromAttributes(), or the Style::parseCssStyle() should check the content of the font-family and prevents it to use a PHAR url, to avoid passing an invalid and dangerous fontName value to other libraries. The same check as done in the Style::fromStyleSheets might be reused :
if (
\array_key_exists("font-family", $styles)
&& (
\strtolower(\substr($this->href, 0, 7)) === "phar://"
|| ($this->document->allowExternalReferences === false && \strtolower(\substr($this->href, 0, 5)) !== "data:")
)
) {
unset($style["font-family"]);
}
PoC
Parsing the following SVG :
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<svg xmlns:svg="http://www.w3.org/2000/svg" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" width="200" height="200">
<text x="20" y="35" style="color:red;font-family:phar:///path/to/whatever.phar/blaklis;">My</text>
</svg>
will pass the phar:///path/to/whatever.phar/blaklis as $family in SurfaceCpdf::setFont, which is then passed to the canvas selectFont as a $fontName.
Impact
Libraries using this library as a dependency might be vulnerable to some bypass of restrictions, or even RCE, if they do not double check the value of the fontName that is passed by php-svg-lib
Untrusted serialized data is processed by a deserializer that can instantiate arbitrary objects or execute code as a side effect. Typical impact: arbitrary code execution or logic abuse.
CVE-2024-25117 has a CVSS score of 6.8 (Medium). The vector is requires local access, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (0.5.2); upgrading removes the vulnerable code path.
Affected versions
Security releases
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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Frequently Asked Questions
- What is CVE-2024-25117? CVE-2024-25117 is a medium-severity insecure deserialization vulnerability in phenx/php-svg-lib (composer), affecting versions < 0.5.2. It is fixed in 0.5.2. Untrusted serialized data is processed by a deserializer that can instantiate arbitrary objects or execute code as a side effect.
- How severe is CVE-2024-25117? CVE-2024-25117 has a CVSS score of 6.8 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of phenx/php-svg-lib are affected by CVE-2024-25117? phenx/php-svg-lib (composer) versions < 0.5.2 is affected.
- Is there a fix for CVE-2024-25117? Yes. CVE-2024-25117 is fixed in 0.5.2. Upgrade to this version or later.
- Is CVE-2024-25117 exploitable, and should I be worried? Whether CVE-2024-25117 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-2024-25117 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-2024-25117? Upgrade
phenx/php-svg-libto 0.5.2 or later.