The DNS protocol in RFC 1035 and updates allows remote attackers to cause a denial of…
Priority HIGH 72CWE-400Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Partial Red Hat: 4 fixed, 3 without a fix
Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA and Red Hat. Impact type from CWE-400.
Summary
The DNS protocol in RFC 1035 and updates allows remote attackers to cause a denial of service (resource consumption) by arranging for DNS queries to be accumulated for seconds, such that responses are later sent in a pulsing burst (which can be considered traffic amplification in some cases), aka the "DNSBomb" issue.
Why it matters now
Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.01743 77th percentileScored 2026-11-07
Fix Partial Red Hat: 2 advisoriesRed Hat: 4 fixed, 3 without a fix
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | — | all versions | — | No fix listed | CNA |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
CPE names CISA-ADP · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:technitium:dns_server:*:*:*:*:*:*:*:* | — | — | Technitium |
- cpe:2.3:a:technitium:dns_server:*:*:*:*:*:*:*:* Versions — — ·Technitium
Remediation
Red Hat 2 advisories
- RHSA-2026:18931 Released 2026-05-19 · Red Hat rating Moderateunbound security update
- Red Hat Enterprise Linux AppStream (v. 9) python3-unbound-1.24.2-2.el9, unbound-1.24.2-2.el9, unbound-dracut-1.24.2-2.el9 +1
- Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) unbound-devel-1.24.2-2.el9
- RHSA-2026:18556 Released 2026-05-19 · Red Hat rating Moderateunbound security update
- Red Hat Enterprise Linux AppStream (v. 10) python3-unbound-1.24.2-7.el10, unbound-1.24.2-7.el10, unbound-anchor-1.24.2-7.el10 +3
- Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) unbound-devel-1.24.2-7.el10
Vendor assessments
Red Hat
Red Hat rating: Low. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 7 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 8 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux AppStream (v. 10) | Fixed | RHSA-2026:18556 |
| Red Hat Enterprise Linux AppStream (v. 9) | Fixed | RHSA-2026:18931 |
| Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) | Fixed | RHSA-2026:18556 |
| Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) | Fixed | RHSA-2026:18931 |
Timeline
- 2026-10-02 Threatist record created from CVE-2024-33655
- 2026-10-03 Alias added: GHSA-2xh4-pf7v-vh6h
References
Other 10
- https://datatracker.ietf.org/doc/html/rfc1035
- https://nlnetlabs.nl/projects/unbound/security-advisories/
- https://github.com/TechnitiumSoftware/DnsServer/blob/master/CHANGELOG.md#version-120
- https://www.isc.org/blogs/2024-dnsbomb/
- https://nlnetlabs.nl/downloads/unbound/CVE-2024-33655.txt
- https://github.com/NLnetLabs/unbound/commit/c3206f4568f60c486be6d165b1f2b5b254fea3de
- https://alas.aws.amazon.com/ALAS-2024-1934.html
- https://meterpreter.org/researchers-uncover-dnsbomb-a-new-pdos-attack-exploiting-legitimate-dns-features/
- https://sp2024.ieee-security.org/accepted-papers.html
- https://gitlab.isc.org/isc-projects/bind9/-/issues/4398
Sources
- CVE-2024-33655 · CVE Program
- CVE-2024-33655 · NVD
- FIRST EPSS
- GHSA-2xh4-pf7v-vh6h · GitHub Advisory Database · CC BY 4.0
- CVE-2024-33655 · Red Hat security data · CC BY 4.0
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