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Fencer Intel
high 8.1

CVE-2019-5440 json

Use of cryptographically weak PRNG in the password recovery token generation of Revive Adserver < v4.2.1 causes a potential authentication…

published 7y ago modified 4mo ago also EUVD-2019-15028

cvss
8.1
version 3.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.6%
EPSS 1.6% chance of exploitation in 30 days, percentile 75%
public exploits
0
none known

Summary

Use of cryptographically weak PRNG in the password recovery token generation of Revive Adserver < v4.2.1 causes a potential authentication bypass attack if an attacker exploits the password recovery functionality. In lib/OA/Dal/PasswordRecovery.php, the function generateRecoveryId() generates a password reset token that relies on the PHP uniqid function and consequently depends only on the current server time, which is often visible in an HTTP Date header.

Patch / fix

  • revive-adserver revive_adserver 4.2.1

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Exploit prediction

1.58% chance of exploitation in the next 30 days, higher than 75% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • hackerone.com https://hackerone.com/reports/576504 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.0 8.1 CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 6.8 AV:N/AC:M/Au:N/C:P/I:P/A:P

Affected products

  • Revive Revive Adserver

Classification

Weakness
  • CWE-338 Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)

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.