Summary
ZendFramework Potential Information Disclosure and Insufficient Entropy vulnerabilities
In Zend Framework 2, the Zend\Math\Rand component generates random bytes using the OpenSSL or Mcrypt extensions when available but will otherwise use PHP's mt_rand() function as a fallback. All outputs from mt_rand() are predictable for the same PHP process if an attacker can brute force the seed used by the Marsenne-Twister algorithm in a Seed Recovery Attack. This attack can be successfully applied with minimum effort if the attacker has access to either a random number from mt_rand() or a Session ID generated without using additional entropy. This makes mt_rand() unsuitable for generating non-trivial random bytes since it has Insufficient Entropy to protect against brute force attacks on the seed.
The Zend\Validate\Csrf component generates CSRF tokens by SHA1 hashing a salt, random number possibly generated using mt_rand() and a form name. Where the salt is known, an attacker can brute force the SHA1 hash with minimum effort to discover the random number when mt_rand() is utilised as a fallback to the OpenSSL and Mcrypt extensions. This constitutes an Information Disclosure where the recovered random number may itself be brute forced to recover the seed value and predict the output of other mt_rand() calls for the same PHP process. This may potentially lead to vulnerabilities in areas of an application where mt_rand() calls exist beyond the scope of Zend Framework.
Impact
Security-sensitive operations rely on values that are predictable or insufficiently random. Typical impact: forged tokens, guessable identifiers, or broken cryptographic protocols.
GHSA-XG9W-R469-M455 has a CVSS score of 7.4 (High). The vector is network-reachable, 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 (2.0.8, 2.1.4); 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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zendframework/zendframework to 2.0.8 or later; zendframework/zendframework to 2.1.4 or later
Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
Frequently Asked Questions
- What is GHSA-XG9W-R469-M455? GHSA-XG9W-R469-M455 is a high-severity use of insufficiently random values vulnerability in zendframework/zendframework (composer), affecting versions >= 2.0.0, < 2.0.8. It is fixed in 2.0.8, 2.1.4. Security-sensitive operations rely on values that are predictable or insufficiently random.
- How severe is GHSA-XG9W-R469-M455? GHSA-XG9W-R469-M455 has a CVSS score of 7.4 (High). 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 zendframework/zendframework are affected by GHSA-XG9W-R469-M455? zendframework/zendframework (composer) versions >= 2.0.0, < 2.0.8 is affected.
- Is there a fix for GHSA-XG9W-R469-M455? Yes. GHSA-XG9W-R469-M455 is fixed in 2.0.8, 2.1.4. Upgrade to this version or later.
- Is GHSA-XG9W-R469-M455 exploitable, and should I be worried? Whether GHSA-XG9W-R469-M455 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 GHSA-XG9W-R469-M455 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 GHSA-XG9W-R469-M455?
- Upgrade
zendframework/zendframeworkto 2.0.8 or later - Upgrade
zendframework/zendframeworkto 2.1.4 or later
- Upgrade