Unbounded name compression could lead to Denial of Service
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||
|---|---|---|---|---|---|---|---|---|---|
| NLnet Labs | Unbound | affected |
|
Configuration 1 [-]
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Configuration 2 [-]
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| Package | CPE | Advisory | Released Date |
|---|---|---|---|
| Red Hat Enterprise Linux 10 | |||
| unbound-0:1.20.0-10.el10_0 | cpe:/o:redhat:enterprise_linux:10.0 | RHSA-2025:8047 | 2025-05-20T00:00:00Z |
| Red Hat Enterprise Linux 8 | |||
| unbound-0:1.16.2-5.8.el8_10 | cpe:/a:redhat:enterprise_linux:8 | RHSA-2025:0837 | 2025-01-30T00:00:00Z |
| Red Hat Enterprise Linux 9 | |||
| unbound-0:1.16.2-8.el9_5.1 | cpe:/a:redhat:enterprise_linux:9 | RHSA-2024:11232 | 2024-12-17T00:00:00Z |
| unbound-0:1.16.2-18.el9_6 | cpe:/a:redhat:enterprise_linux:9 | RHSA-2025:8197 | 2025-05-27T00:00:00Z |
| Red Hat Enterprise Linux 9.4 Extended Update Support | |||
| unbound-0:1.16.2-8.el9_4.1 | cpe:/a:redhat:rhel_eus:9.4 | RHSA-2024:11170 | 2024-12-17T00:00:00Z |
| Red Hat OpenShift Container Platform 4.16 | |||
| rhcos-416.94.202501030250-0 | cpe:/a:redhat:openshift:4.16::el9 | RHSA-2025:0140 | 2025-01-15T00:00:00Z |
| Red Hat OpenShift Container Platform 4.17 | |||
| rhcos-417.94.202502051822-0 | cpe:/a:redhat:openshift:4.17::el9 | RHSA-2025:1120 | 2025-02-11T00:00:00Z |
No data available yet.
Vendor Solution
This issue is fixed in 1.21.1 and all later versions.
| Source | ID | Title |
|---|---|---|
Debian DLA |
DLA-3952-1 | unbound security update |
Debian DSA |
DSA-5987-1 | unbound security update |
EUVD |
EUVD-2024-49228 | NLnet Labs Unbound up to and including version 1.21.0 contains a vulnerability when handling replies with very large RRsets that it needs to perform name compression for. Malicious upstreams responses with very large RRsets can cause Unbound to spend a considerable time applying name compression to downstream replies. This can lead to degraded performance and eventually denial of service in well orchestrated attacks. The vulnerability can be exploited by a malicious actor querying Unbound for the specially crafted contents of a malicious zone with very large RRsets. Before Unbound replies to the query it will try to apply name compression which was an unbounded operation that could lock the CPU until the whole packet was complete. Unbound version 1.21.1 introduces a hard limit on the number of name compression calculations it is willing to do per packet. Packets that need more compression will result in semi-compressed packets or truncated packets, even on TCP for huge messages, to avoid locking the CPU for long. This change should not affect normal DNS traffic. |
Ubuntu USN |
USN-7080-1 | Unbound vulnerability |
No CVSS v4.0
No CVSS v3.0
No CVSS v2
This CVE is not in the KEV list.
Exploit prediction score: < 1% (0.801% probability within 30 days)
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
epss
|
epss
|
| Type | Values Removed | Values Added |
|---|---|---|
| CPEs | cpe:/o:redhat:enterprise_linux:10.0 |
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Redhat openshift
|
|
| CPEs | cpe:/a:redhat:enterprise_linux:8 cpe:/a:redhat:openshift:4.16::el9 cpe:/a:redhat:openshift:4.17::el9 |
|
| Vendors & Products |
Redhat openshift
|
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Redhat
Redhat enterprise Linux Redhat rhel Eus |
|
| CPEs | cpe:/a:redhat:enterprise_linux:9 cpe:/a:redhat:rhel_eus:9.4 |
|
| Vendors & Products |
Redhat
Redhat enterprise Linux Redhat rhel Eus |
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Debian
Debian debian Linux |
|
| Weaknesses | CWE-1284 | |
| CPEs | cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:* | |
| Vendors & Products |
Debian
Debian debian Linux |
| Type | Values Removed | Values Added |
|---|---|---|
| References |
|
| Type | Values Removed | Values Added |
|---|---|---|
| References |
| |
| Metrics |
threat_severity
|
threat_severity
|
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Nlnetlabs
Nlnetlabs unbound |
|
| CPEs | cpe:2.3:a:nlnetlabs:unbound:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Nlnetlabs
Nlnetlabs unbound |
|
| Metrics |
ssvc
|
| Type | Values Removed | Values Added |
|---|---|---|
| Description | NLnet Labs Unbound up to and including version 1.21.0 contains a vulnerability when handling replies with very large RRsets that it needs to perform name compression for. Malicious upstreams responses with very large RRsets can cause Unbound to spend a considerable time applying name compression to downstream replies. This can lead to degraded performance and eventually denial of service in well orchestrated attacks. The vulnerability can be exploited by a malicious actor querying Unbound for the specially crafted contents of a malicious zone with very large RRsets. Before Unbound replies to the query it will try to apply name compression which was an unbounded operation that could lock the CPU until the whole packet was complete. Unbound version 1.21.1 introduces a hard limit on the number of name compression calculations it is willing to do per packet. Packets that need more compression will result in semi-compressed packets or truncated packets, even on TCP for huge messages, to avoid locking the CPU for long. This change should not affect normal DNS traffic. | |
| Title | Unbounded name compression could lead to Denial of Service | |
| Weaknesses | CWE-606 | |
| References |
| |
| Metrics |
cvssV3_1
|