CVE-2025-40780CWE-341

CVE-2025-40780

High · published October 22, 2025

CVSS v3.1
8.6
EPSS
0%
Percentile
39.4
In the wild
Unconfirmed
What it is

⚡ A flaw in the Pseudo Random Number Generator (PRNG) used by BIND could allow attackers to predict source ports and query IDs—essentially cracking the code to unlock sensitive communications! 🔓 Think of the PRNG as a coffee machine that should randomly brew different blends each time, but instead, it ends up serving the same cup over and over. An attacker could guess the next brew, knowing the machine's faulty recipe! ☕️ With the ability to predict the source port and query ID, an attacker could hijack DNS queries. This could lead to data interception, unauthorized access to services, or even directing users to malicious sites without their knowledge! The potential for chaos is absolutely devastating!

Put simply

Think of the PRNG as a coffee machine that should randomly brew different blends each time, but instead, it ends up serving the same cup over and over. An attacker could guess the next brew, knowing the machine's faulty recipe! ☕️ This vulnerability arises from a weakness in the Pseudo Random Number Generator (PRNG) in BIND, allowing attackers to predict certain network parameters in DNS communications, which can facilitate various attacks.

What to do

With the ability to predict the source port and query ID, an attacker could hijack DNS queries. This could lead to data interception, unauthorized access to services, or even directing users to malicious sites without their knowledge! The potential for chaos is absolutely devastating! To protect your systems, upgrade BIND to the fixed version 9.16.51, 9.18.40, 9.20.14, or 9.21.13. Regularly review your DNS configurations and consider enabling additional security measures like DNSSEC. 🛡️ You're on the right track! Follow these steps, and you'll have your defenses bolstered in no time. You've got this! 💪✨

The record
Technical detail
CVSS v3.1
8.6 · HIGH
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N
CVSS v4.0
Not supplied
EPSS
0.00466 · 39.4th percentile
Weakness
CWE-341 · Predictable from Observable State
Published
2025-10-22T20:15Z
References (2)
EPSS history
Timeline
  • 22 OCT 15:48Z
    Cache poisoning due to weak PRNG
    cvelistv5