CVE-2020-10772 Denial of service in unbound
Incomplete fix allows Unbound DNS resolver to amplify queries, enabling denial of service attacks against targets.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2020-10772?
CVE-2020-10772 is a high-severity denial of service vulnerability in Nlnetlabs Unbound, published on 27 Nov 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
An incomplete fix for CVE-2020-12662 was shipped for Unbound in Red Hat Enterprise Linux 7, as part of erratum RHSA-2020:2414. Vulnerable versions of Unbound could still amplify an incoming query into a large number of queries directed to a target, even with a lower amplification ratio compared to versions of Unbound that shipped before the mentioned erratum. This issue is about the incomplete fix for CVE-2020-12662, and it does not affect upstream versions of Unbound.
Which versions are affected by CVE-2020-10772?
It affects 1 product.
Linux distribution packages (20)
unbound Red Hat:enterprise_linux:7::client | All versions | 0:1.6.6-5.el7_8 |
unbound-debuginfo Red Hat:enterprise_linux:7::client | All versions | 0:1.6.6-5.el7_8 |
unbound-devel Red Hat:enterprise_linux:7::client | All versions | 0:1.6.6-5.el7_8 |
unbound-libs Red Hat:enterprise_linux:7::client | All versions | 0:1.6.6-5.el7_8 |
unbound-python Red Hat:enterprise_linux:7::client | All versions | 0:1.6.6-5.el7_8 |
unbound Red Hat:enterprise_linux:7::computenode | All versions | 0:1.6.6-5.el7_8 |
unbound-debuginfo Red Hat:enterprise_linux:7::computenode | All versions | 0:1.6.6-5.el7_8 |
unbound-devel Red Hat:enterprise_linux:7::computenode | All versions | 0:1.6.6-5.el7_8 |
unbound-libs Red Hat:enterprise_linux:7::computenode | All versions | 0:1.6.6-5.el7_8 |
unbound-python Red Hat:enterprise_linux:7::computenode | All versions | 0:1.6.6-5.el7_8 |
unbound Red Hat:enterprise_linux:7::server | All versions | 0:1.6.6-5.el7_8 |
unbound-debuginfo Red Hat:enterprise_linux:7::server | All versions | 0:1.6.6-5.el7_8 |
unbound-devel Red Hat:enterprise_linux:7::server | All versions | 0:1.6.6-5.el7_8 |
unbound-libs Red Hat:enterprise_linux:7::server | All versions | 0:1.6.6-5.el7_8 |
unbound-python Red Hat:enterprise_linux:7::server | All versions | 0:1.6.6-5.el7_8 |
unbound Red Hat:enterprise_linux:7::workstation | All versions | 0:1.6.6-5.el7_8 |
unbound-debuginfo Red Hat:enterprise_linux:7::workstation | All versions | 0:1.6.6-5.el7_8 |
unbound-devel Red Hat:enterprise_linux:7::workstation | All versions | 0:1.6.6-5.el7_8 |
unbound-libs Red Hat:enterprise_linux:7::workstation | All versions | 0:1.6.6-5.el7_8 |
unbound-python Red Hat:enterprise_linux:7::workstation | All versions | 0:1.6.6-5.el7_8 |
Products include Nlnetlabs Unbound.
How do I fix CVE-2020-10772?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2020-10772 being exploited?
There is no known exploitation of CVE-2020-10772 in the wild and no public exploit code.
Other vulnerabilities in Nlnetlabs Unbound
- CVE-2026-81642 Heap buffer overflow and possible Remote Code Execution when digesting DNSKEY
- CVE-2026-33278 Possible arbitrary code execution during DNSSEC validation
- CVE-2026-42944 Heap overflow with multiple NSID, COOKIE, PADDING EDNS options
- CVE-2026-42959 Crash during DNSSEC validation of malicious content
- CVE-2026-82717 CNAME synthesis could lead to heap corruption
Sources
Also known as GHSA-g6qm-p3jr-vj64, RHSA-2020:2642.