Out-of-bounds Read in Butok Fnet

CVE-2020-17467

An issue was discovered in FNET through 4.6.4. The code for processing the hostname from an LLMNR request doesn't check for '\0' termination. Therefore, the deduced length of the hostname doesn't reflect the correct length of the actual data. This may lead to Information Disclosure in _fnet_llmnr_poll in fnet_llmnr.c during a response to a malicious request of the DNS class IN.

Vulnerability class: Buffer Overflow

EPSS: 0.030 (86.1th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H.

Affected products

Weakness classification (CWE)

References

  • cve@mitre.org (US Government Resource, Third Party Advisory, x_refsource_MISC)
  • cve@mitre.org (US Government Resource, Third Party Advisory, x_refsource_MISC)
  • cve@mitre.org (x_refsource_CONFIRM, Third Party Advisory, Release Notes)

Frequently asked questions

What is CVE-2020-17467?
CVE-2020-17467 is a critical-severity vulnerability in Butok Fnet, classified under Out-of-bounds Read. CVSS score: 9.1/10. Published 2020-12-11.
How severe is CVE-2020-17467?
Critical severity. CVSS v3 base score is 9.1 out of 10.