named configured to answer from stale cache may terminate unexpectedly while processing RRSIG queries
BIND 9 resolver can crash when stale cache and stale answers are enabled, option `stale-answer-client-timeout` is set to a positive integer, and the resolver receives an RRSIG query. This issue affects BIND 9 versions 9.16.12 through 9.16.36, 9.18.0 through 9.18.10, 9.19.0 through 9.19.8, and 9.16.12-S1 through 9.16.36-S1.
- Published
- Jan 26, 2023
- Updated
- Jun 17, 2026
- EPSS
- 48.7% · 99th percentile
- CWE
- CWE-20
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Report tools
Action score
45
Plan
Add it to your regular patch cycle.
- CVSS
- 30 / 40 · 7.5 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 15 / 30 · 48.7%
CISA SSVC decision
- Exploitation
- none
- Automatable
- yes
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- 7.5
- CNA · isc
- 7.5
- agree
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for the hundreds of thousands of vulnerabilities in the database; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpAffected systems
| Vendor | Product | CPE |
|---|---|---|
| isc | bind | cpe:2.3:a:isc:bind |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- isc bind9.16.12 and later · before 9.16.37
- isc bind9.18.0 and later · before 9.18.11
- isc bind9.19.0 and later · before 9.19.9
- isc bind9.16.11
- isc bind9.16.13
- isc bind9.16.14
- isc bind9.16.21
- isc bind9.16.32
- isc bind9.16.36
Versions reported by the vendor
Affected version ranges reported by the assigning authority (isc). Independent of NVD's CPE analysis and usually ahead of it.
ISC BIND 9
- 9.16.12 and later · up to and including 9.16.36affected
- 9.18.0 and later · up to and including 9.18.10affected
- 9.19.0 and later · up to and including 9.19.8affected
- 9.16.12-S1 and later · up to and including 9.16.36-S1affected
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| AlmaLinux:8 | bind9.16 | before 32:9.16.23-0.14.el8 | 32:9.16.23-0.14.el8 |
| AlmaLinux:8 | bind9.16-chroot | before 32:9.16.23-0.14.el8 | 32:9.16.23-0.14.el8 |
| AlmaLinux:8 | bind9.16-devel | before 32:9.16.23-0.14.el8 | 32:9.16.23-0.14.el8 |
| AlmaLinux:8 | bind9.16-dnssec-utils | before 32:9.16.23-0.14.el8 | 32:9.16.23-0.14.el8 |
| AlmaLinux:8 | bind9.16-doc | before 32:9.16.23-0.14.el8 | 32:9.16.23-0.14.el8 |
| AlmaLinux:8 | bind9.16-libs | before 32:9.16.23-0.14.el8 | 32:9.16.23-0.14.el8 |
| AlmaLinux:8 | bind9.16-license | before 32:9.16.23-0.14.el8 | 32:9.16.23-0.14.el8 |
| AlmaLinux:8 | bind9.16-utils | before 32:9.16.23-0.14.el8 | 32:9.16.23-0.14.el8 |
| AlmaLinux:8 | python3-bind9.16 | before 32:9.16.23-0.14.el8 | 32:9.16.23-0.14.el8 |
| AlmaLinux:9 | bind | before 32:9.16.23-11.el9 | 32:9.16.23-11.el9 |
| AlmaLinux:9 | bind-chroot | before 32:9.16.23-11.el9 | 32:9.16.23-11.el9 |
| AlmaLinux:9 | bind-devel | before 32:9.16.23-11.el9 | 32:9.16.23-11.el9 |
| AlmaLinux:9 | bind-dnssec-doc | before 32:9.16.23-11.el9 | 32:9.16.23-11.el9 |
| AlmaLinux:9 | bind-dnssec-utils | before 32:9.16.23-11.el9 | 32:9.16.23-11.el9 |
| AlmaLinux:9 | bind-doc | before 32:9.16.23-11.el9 | 32:9.16.23-11.el9 |
| AlmaLinux:9 | bind-libs | before 32:9.16.23-11.el9 | 32:9.16.23-11.el9 |
| AlmaLinux:9 | bind-license | before 32:9.16.23-11.el9 | 32:9.16.23-11.el9 |
| AlmaLinux:9 | bind-utils | before 32:9.16.23-11.el9 | 32:9.16.23-11.el9 |
| AlmaLinux:9 | python3-bind | before 32:9.16.23-11.el9 | 32:9.16.23-11.el9 |
| Alpine:v3.14 | bind | from 9.16.12 · before 9.16.37-r0 | 9.16.37-r0 |
| Alpine:v3.17 | bind | from 9.16.12 · before 9.18.11-r0 | 9.18.11-r0 |
| Debian:11 | bind9 | before 1:9.16.37-1~deb11u1 | 1:9.16.37-1~deb11u1 |
| Debian:12 | bind9 | before 1:9.18.11-1 | 1:9.18.11-1 |
| openSUSE:Tumbleweed | bind | before 9.18.11-1.1 | 9.18.11-1.1 |
+31
Same product
isc: all recordsOther highest-scoring records for the same primary product.
- CVE-2015-5477named in ISC BIND 9.x before 9.9.7-P2 and 9.10.x before 9.10.2-P3 allows remote attackers to cause a denial of service (REQUIRE assertion fa58Plan
- CVE-2016-2776buffer.c in named in ISC BIND 9 before 9.9.9-P3, 9.10.x before 9.10.4-P3, and 9.11.x before 9.11.0rc3 does not properly construct responses,57Plan
- CVE-2016-1286named in ISC BIND 9.x before 9.9.8-P4 and 9.10.x before 9.10.3-P4 allows remote attackers to cause a denial of service (assertion failure an53Plan
- CVE-2020-8625A vulnerability in BIND's GSSAPI security policy negotiation can be targeted by a buffer overflow attack51Plan
- CVE-2020-8617A logic error in code which checks TSIG validity can be used to trigger an assertion failure in tsig.c51Plan
- CVE-2001-0010Buffer overflow in transaction signature (TSIG) handling code in BIND 8 allows remote attackers to gain root privileges.49Plan
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| almalinux:bind | 32:9.16.23-11.el9 · AlmaLinux:9 | Package registry (OSV) |
| almalinux:bind-chroot | 32:9.16.23-11.el9 · AlmaLinux:9 | Package registry (OSV) |
| almalinux:bind-devel | 32:9.16.23-11.el9 · AlmaLinux:9 | Package registry (OSV) |
| almalinux:bind-dnssec-doc | 32:9.16.23-11.el9 · AlmaLinux:9 | Package registry (OSV) |
| almalinux:bind-dnssec-utils | 32:9.16.23-11.el9 · AlmaLinux:9 | Package registry (OSV) |
| almalinux:bind-doc | 32:9.16.23-11.el9 · AlmaLinux:9 | Package registry (OSV) |
| almalinux:bind-libs | 32:9.16.23-11.el9 · AlmaLinux:9 | Package registry (OSV) |
| almalinux:bind-license | 32:9.16.23-11.el9 · AlmaLinux:9 | Package registry (OSV) |
| almalinux:bind-utils | 32:9.16.23-11.el9 · AlmaLinux:9 | Package registry (OSV) |
| almalinux:bind9.16 | 32:9.16.23-0.14.el8 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:bind9.16-chroot | 32:9.16.23-0.14.el8 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:python3-bind | 32:9.16.23-11.el9 · AlmaLinux:9 | Package registry (OSV) |
| alpine:bind | 9.16.37-r0 · Alpine:v3.14 | Package registry (OSV) |
| debian:bind9 | 1:9.18.11-1 · Debian:12 | Package registry (OSV) |
| opensuse:bind | 9.16.37-150400.5.17.1 · openSUSE:Leap 15.4 | Package registry (OSV) |
| red hat:bind | 32:9.16.23-11.el9 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| red hat:bind-chroot | 32:9.16.23-11.el9 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| red hat:bind-debuginfo | 32:9.16.23-11.el9 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| red hat:bind-debugsource | 32:9.16.23-11.el9 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| red hat:bind-dnssec-doc | 32:9.16.23-11.el9 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| red hat:bind-dnssec-utils | 32:9.16.23-11.el9 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| red hat:bind-dnssec-utils-debuginfo | 32:9.16.23-11.el9 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| red hat:bind-libs | 32:9.16.23-11.el9 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| red hat:bind-libs-debuginfo | 32:9.16.23-11.el9 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| red hat:bind-license | 32:9.16.23-11.el9 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| red hat:bind-utils | 32:9.16.23-11.el9 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| red hat:bind-utils-debuginfo | 32:9.16.23-11.el9 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| suse:bind | 9.16.37-150400.5.17.1 · SUSE:Linux Enterprise Module for Basesystem 15 SP4 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
- Borja MarcosSarenet (with assistance by Iratxe Niño from Fundación Sarenet) for bringing this vulnerability to our attention.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- none
- Integrity
- none
- Availability
- high · the service can be disrupted
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- None
- Integrity impact
- None
- Availability impact
- High
Weakness class (CWE)
CWE-20 · Improper Input ValidationCVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
nvd-primary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
- Buffer Overflow via Environment VariablesCAPEC-10likelihood: High · High
- Server Side Include (SSI) InjectionCAPEC-101likelihood: High · High
- Cross Zone ScriptingCAPEC-104likelihood: Medium · High
- Command Line Execution through SQL InjectionCAPEC-108likelihood: Low · Very High
- Object Relational Mapping InjectionCAPEC-109likelihood: Low · High
- SQL Injection through SOAP Parameter TamperingCAPEC-110likelihood: High · Very High
- Double EncodingCAPEC-120likelihood: Low · Medium
- Subverting Environment Variable ValuesCAPEC-13likelihood: High · Very High
ATT&CK techniques
- Obfuscated Files or InformationT1027
- Masquerading: Invalid Code SignatureT1036.001
- Steal Web Session CookieT1539
- Subvert Trust Controls: Code SigningT1553.002
- Impair Defenses:Impair Command History LoggingT1562.003
- Hijack Execution Flow:Dynamic Linker HijackingT1574.006
- Hijack Execution Flow:Path Interception by PATH Environment VariableT1574.007
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Vendor advisories and official records. Exploit/PoC links are deliberately left out.