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Fencer Intel
high 7.5

GHSA-mg4x-prh7-g4mx json

Zend-Captcha Information Disclosure and Insufficient Entropy vulnerability

published 2y ago modified last yr.

cvss
7.5
version 3.1, GitHub
cisa kev
Not listed
not in CISA's catalog
epss
—
no score, EPSS covers CVEs only
public exploits
0
none known

Summary

In Zend Framework, `Zend_Captcha_Word` (v1) and `Zend\Captcha\Word` (v2) generate a "word" for a CAPTCHA challenge by selecting a sequence of random letters from a character set. Prior to this advisory, the selection was performed using PHP's internal `array_rand()` function. This function does not generate sufficient entropy due to its usage of rand() instead of more cryptographically secure methods such as `openssl_pseudo_random_bytes()`. This could potentially lead to information disclosure should an attacker be able to brute force the random number generation.

Patch / fix

  • packagist zendframework/zend-captcha 2.4.9, 2.5.2

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CVSS scores

assigned by version score vector
GitHub 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Affected packages

ecosystem package affected fixed in
packagist zendframework/zend-captcha
>=2.0.0, <2.4.9
>=2.5.0, <2.5.2
2.4.9
2.5.2

Classification

Weakness

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.