7.5

CVE-2023-4236: debian debian_linux Reachable Assertion

CVSS: 7.5v3.1HighModified
AliasesALPINE-CVE-2023-4236UBUNTU-CVE-2023-4236DEBIAN-CVE-2023-4236
Published 20-09-2023Last modified 13-02-2025
Open JSON

Vulnerability summary

CVE-2023-4236 is a high (CVSS 7.5) Reachable Assertion vulnerability in debian debian_linux. EPSS estimates a 2.21% chance of exploitation in the next 30 days, higher than 82.3% of scored vulnerabilities.

Overall risk
30/100
0100
Medium · default modelHow is this calculated?
CVSS score
7.5/10
010
High · v3.1 (CVE.org)
EPSS score
2.21%
0%100%
Low · +0.04 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 3 · Related 2
MGASA-2023-0303OPENSUSE-SU-2024:13249-1USN-6390-1

Timeline

  1. 20-09-2023
    PublishedVulnerability first disclosed.
  2. 13-02-2025
    Last modifiedVulnerability information updated.

Description

A flaw in the networking code handling DNS-over-TLS queries may cause `named` to terminate unexpectedly due to an assertion failure. This happens when internal data structures are incorrectly reused under significant DNS-over-TLS query load. This issue affects BIND 9 versions 9.18.0 through 9.18.18 and 9.18.11-S1 through 9.18.18-S1.

CVSS metrics

5 scores · 5 sources · 1 version

EPSS trend

Probability

2.21%

Chance of exploitation in the next 30 days

Percentile

82%

Versus all other CVEs

30-day change

+0.04 pp

From 2.17% on 19-09-2026

19-09-202619-10-2026
EPSS score
2.21%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Netapp5 products
Debian2 products
  • bind9< 1:9.18.19-1~deb12u1 | < 1:9.19.17-1
  • debian_linuxEOL10.0 | 11.0
Isc2 products
  • bind≥ 9.18.0, < 9.18.18 | 9.18.11:s1 | 9.18.18:s1
  • bind 9≥ 9.18.0, ≤ 9.18.18 | ≥ 9.18.11-S1, ≤ 9.18.18-S1
Alpine1 product
  • bind≥ 9.18.0, < 9.18.19-r0
Fedoraproject1 product
Ubuntu1 product
  • bind9< 1:9.18.12-0ubuntu0.22.04.3 | < 1:9.18.18-0ubuntu2

6 vendors · 12 products

References

12 links
Show all 12 references