CVE-2023-50387: Certain DNSSEC aspects of the DNS protocol (in RFC 4033, 4034, 4035, 6840, and related RFCs) allow remote attackers to cause a denial of ser
Noroxi assessment
Priority: This week (action score 60/100)
- Public proof-of-concept code exists (GitHub); there is no record of exploitation in the wild.
- Probability of exploitation in the next 30 days: 99.9% (FIRST EPSS); higher than 99.9% of all records.
- 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.
- According to CISA the attack is automatable: targets can be found by mass scanning.
- Fixed version: bind (AlmaLinux:8) 32:9.11.36-11.el8_9.1, 32:9.11.36-14.el8_10; bind-chroot (AlmaLinux:8) 32:9.11.36-14.el8_10, 32:9.11.36-11.el8_9.1; bind-devel (AlmaLinux:8) 32:9.11.36-14.el8_10, 32:9.11.36-11.el8_9.1.
Don’t wait for the next maintenance window. Upgrade to bind (AlmaLinux:8) 32:9.11.36-11.el8_9.1, 32:9.11.36-14.el8_10; bind-chroot (AlmaLinux:8) 32:9.11.36-14.el8_10, 32:9.11.36-11.el8_9.1; bind-devel (AlmaLinux:8) 32:9.11.36-14.el8_10, 32:9.11.36-11.el8_9.1 or later.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
Primary sources: NVD · CVE.org · FIRST EPSS
Certain DNSSEC aspects of the DNS protocol (in RFC 4033, 4034, 4035, 6840, and related RFCs) allow remote attackers to cause a denial of service (CPU consumption) via one or more DNSSEC responses, aka the "KeyTrap" issue. One of the concerns is that, when there is a zone with many DNSKEY and RRSIG records, the protocol specification implies that an algorithm must evaluate all combinations of DNSKEY and RRSIG records.
- Published
- Feb 14, 2024
- Updated
- Jun 17, 2026
- EPSS
- 99.9% · 99th percentile
- CWE
- CWE-770
Report tools
Action score
60
This week
Don’t wait for the next maintenance window.
- CVSS
- 30 / 40 · 7.5 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 30 / 30 · 99.9%
CISA SSVC decision
- Exploitation
- none
- Automatable
- yes
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- Proof of concept exists, no weaponized module
- A fix has been released
If any of these changes, we'll tell you in the daily email digest.
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Noroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
| Vendor | Product | CPE |
|---|---|---|
| redhat | enterprise linux | cpe:2.3:o:redhat:enterprise_linux |
| microsoft | windows server 2008 | cpe:2.3:o:microsoft:windows_server_2008 |
| microsoft | windows server 2012 | cpe:2.3:o:microsoft:windows_server_2012 |
| microsoft | windows server 2016 | cpe:2.3:o:microsoft:windows_server_2016 |
| microsoft | windows server 2019 | cpe:2.3:o:microsoft:windows_server_2019 |
| microsoft | windows server 2022 | cpe:2.3:o:microsoft:windows_server_2022 |
| microsoft | windows server 2022 23h2 | cpe:2.3:o:microsoft:windows_server_2022_23h2 |
| fedoraproject | fedora | cpe:2.3:o:fedoraproject:fedora |
| thekelleys | dnsmasq | cpe:2.3:a:thekelleys:dnsmasq |
| nic | knot resolver | cpe:2.3:a:nic:knot_resolver |
| powerdns | recursor | cpe:2.3:a:powerdns:recursor |
| isc | bind | cpe:2.3:a:isc:bind |
and 1 more
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- microsoft windows server 2008r2
- microsoft windows server 2012all versions
- microsoft windows server 2012r2
- microsoft windows server 2016all versions
- microsoft windows server 2019all versions
- microsoft windows server 2022all versions
- microsoft windows server 2022 23h2all versions
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| AlmaLinux:8 | bind | before 32:9.11.36-11.el8_9.1 | 32:9.11.36-11.el8_9.1 |
| AlmaLinux:8 | bind | before 32:9.11.36-14.el8_10 | 32:9.11.36-14.el8_10 |
| AlmaLinux:8 | bind-chroot | before 32:9.11.36-14.el8_10 | 32:9.11.36-14.el8_10 |
| AlmaLinux:8 | bind-chroot | before 32:9.11.36-11.el8_9.1 | 32:9.11.36-11.el8_9.1 |
| AlmaLinux:8 | bind-devel | before 32:9.11.36-14.el8_10 | 32:9.11.36-14.el8_10 |
| AlmaLinux:8 | bind-devel | before 32:9.11.36-11.el8_9.1 | 32:9.11.36-11.el8_9.1 |
| AlmaLinux:8 | bind-export-devel | before 32:9.11.36-11.el8_9.1 | 32:9.11.36-11.el8_9.1 |
| AlmaLinux:8 | bind-export-devel | before 32:9.11.36-14.el8_10 | 32:9.11.36-14.el8_10 |
| AlmaLinux:8 | bind-export-libs | before 32:9.11.36-14.el8_10 | 32:9.11.36-14.el8_10 |
| AlmaLinux:8 | bind-export-libs | before 32:9.11.36-11.el8_9.1 | 32:9.11.36-11.el8_9.1 |
| AlmaLinux:8 | bind-libs | before 32:9.11.36-11.el8_9.1 | 32:9.11.36-11.el8_9.1 |
| AlmaLinux:8 | bind-libs | before 32:9.11.36-14.el8_10 | 32:9.11.36-14.el8_10 |
| AlmaLinux:8 | bind-libs-lite | before 32:9.11.36-11.el8_9.1 | 32:9.11.36-11.el8_9.1 |
| AlmaLinux:8 | bind-libs-lite | before 32:9.11.36-14.el8_10 | 32:9.11.36-14.el8_10 |
| AlmaLinux:8 | bind-license | before 32:9.11.36-14.el8_10 | 32:9.11.36-14.el8_10 |
| AlmaLinux:8 | bind-license | before 32:9.11.36-11.el8_9.1 | 32:9.11.36-11.el8_9.1 |
| AlmaLinux:8 | bind-lite-devel | before 32:9.11.36-11.el8_9.1 | 32:9.11.36-11.el8_9.1 |
| AlmaLinux:8 | bind-lite-devel | before 32:9.11.36-14.el8_10 | 32:9.11.36-14.el8_10 |
| AlmaLinux:8 | bind-pkcs11 | before 32:9.11.36-14.el8_10 | 32:9.11.36-14.el8_10 |
| AlmaLinux:8 | bind-pkcs11 | before 32:9.11.36-11.el8_9.1 | 32:9.11.36-11.el8_9.1 |
| AlmaLinux:8 | bind-pkcs11-devel | before 32:9.11.36-11.el8_9.1 | 32:9.11.36-11.el8_9.1 |
| AlmaLinux:8 | bind-pkcs11-devel | before 32:9.11.36-14.el8_10 | 32:9.11.36-14.el8_10 |
| AlmaLinux:8 | bind-pkcs11-libs | before 32:9.11.36-14.el8_10 | 32:9.11.36-14.el8_10 |
| AlmaLinux:8 | bind-pkcs11-libs | before 32:9.11.36-11.el8_9.1 | 32:9.11.36-11.el8_9.1 |
+96
Same product
redhat: all recordsOther highest-scoring records for the same primary product.
- CVE-2015-3246libuser before 0.56.13-8 and 0.60 before 0.60-7, as used in the userhelper program in the usermode package, directly modifies /etc/passwd, wKEV62This week
- CVE-2017-5456A mechanism to bypass file system access protections in the sandbox using the file system request constructor through an IPC message.40Plan
- CVE-2017-5428An integer overflow in "createImageBitmap()" was reported through the Pwn2Own contest.40Plan
Published before and after this one in the same product
- ← EarlierCVE-2023-6121Nov 16, 2023 · Kernel: nvme: info leak due to out-of-bounds read in nvmet_ctrl_find_get17Monitor
- ← EarlierCVE-2023-50781Feb 5, 2024 · M2crypto: bleichenbacher timing attacks in the rsa decryption api - incomplete fix for cve-2020-2565730Monitor
- Later →CVE-2024-3183Jun 12, 2024 · Freeipa: user can obtain a hash of the passwords of all domain users and perform offline brute force33Monitor
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:bind9.16 | 32:9.16.23-0.16.el8_9.2.alma.1 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:bind9.16-chroot | 32:9.16.23-0.16.el8_9.2.alma.1 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:bind9.16-devel | 32:9.16.23-0.16.el8_9.2.alma.1 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:bind9.16-dnssec-utils | 32:9.16.23-0.16.el8_9.2.alma.1 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:bind9.16-doc | 32:9.16.23-0.16.el8_9.2.alma.1 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:bind9.16-libs | 32:9.16.23-0.16.el8_9.2.alma.1 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:dnsmasq | 2.85-14.el9_3.1 · AlmaLinux:9 | Package registry (OSV) |
| almalinux:dnsmasq-utils | 2.85-14.el9_3.1 · AlmaLinux:9 | Package registry (OSV) |
| almalinux:python3-unbound | 1.16.2-5.el8_9.2 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:unbound | 1.16.2-5.el8_9.2 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:unbound-devel | 1.16.2-5.el8_9.2 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:unbound-libs | 1.16.2-5.el8_9.2 · AlmaLinux:8 | Package registry (OSV) |
| alpine:bind | 9.16.48-r0 · Alpine:v3.16 | Package registry (OSV) |
| alpine:dnsmasq | 2.90-r0 · Alpine:v3.17 | Package registry (OSV) |
| alpine:knot-resolver | 5.7.1-r0 · Alpine:v3.18 | Package registry (OSV) |
| alpine:pdns-recursor | 4.9.3-r0 · Alpine:v3.18 | Package registry (OSV) |
| alpine:unbound | 1.19.1-r0 · Alpine:v3.17 | Package registry (OSV) |
| debian:bind9 | 1:9.18.24-1 · Debian:12 | Package registry (OSV) |
| debian:dnsjava | 3.6.2-1 · Debian:13 | Package registry (OSV) |
| debian:dnsmasq | 2.90-4~deb12u1 · Debian:12 | Package registry (OSV) |
| debian:knot-resolver | 5.6.0-1+deb12u1 · Debian:12 | Package registry (OSV) |
| debian:pdns-recursor | 4.8.6-1 · Debian:12 | Package registry (OSV) |
| debian:systemd | 252.23-1~deb12u1 · Debian:12 | Package registry (OSV) |
| debian:unbound | 1.17.1-2+deb12u2 · Debian:12 | Package registry (OSV) |
| opensuse:bind | 9.16.48-150500.8.16.1 · openSUSE:Leap 15.5 | Package registry (OSV) |
| opensuse:dnsmasq | 2.90-150400.16.3.1 · openSUSE:Leap Micro 5.5 | Package registry (OSV) |
| opensuse:pdns-recursor | 4.8.6-bp155.2.3.1 · openSUSE:Leap 15.5 | Package registry (OSV) |
| opensuse:unbound | 1.20.0-150600.23.3.1 · openSUSE:Leap 15.6 | Package registry (OSV) |
| red hat:dnsmasq | 0:2.85-14.el9_3.1 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| red hat:dnsmasq-debuginfo | 0:2.85-14.el9_3.1 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
+20
Exploit status
Proof of concept available
A public proof of concept or detection signature exists. Exploit knowledge is out there; don't delay patching.
Evidence
- Proof-of-concept repository on GitHub ×3
Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.
| Source | Kind | Date |
|---|---|---|
| Proof-of-concept repository on GitHub | stars:44 | 2024-02-18 |
| Proof-of-concept repository on GitHub | stars:0 | 2024-05-23 |
| Proof-of-concept repository on GitHub | stars:0 | 2024-12-04 |
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.
- Published
- First PoC+3 d
- TodayNov 7, 2026+997 d
No history yet (it accumulates with the daily EPSS job).
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.
No credits in the CNA record.
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-770 · Allocation of Resources Without Limits or ThrottlingCVSS 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)
- FloodingCAPEC-125likelihood: High · Medium
- Excessive AllocationCAPEC-130likelihood: Medium · Medium
- XML Ping of the DeathCAPEC-147likelihood: Low · Medium
- Exponential Data ExpansionCAPEC-197likelihood: High · Medium
- Serialized Data Parameter BlowupCAPEC-229likelihood: High · High
- Serialized Data with Nested PayloadsCAPEC-230likelihood: Medium · High
- Oversized Serialized Data PayloadsCAPEC-231likelihood: Medium · High
- HTTP DoSCAPEC-469Low
ATT&CK techniques
- Network Denial of Service:Direct Network FloodT1498.001
- Network Denial of Service:Reflection AmplificationT1498.002
- Endpoint Denial of ServiceT1499
- Endpoint Denial of Service: OS Exhaustion FloodT1499.001
- Endpoint Denial of Service:Service Exhaustion FloodT1499.002
- Endpoint Denial of Service:Application Exhaustion FloodT1499.003
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (19 more)Show less
- www.openwall.com/lists/oss-security/2024/02/16/3
- access.redhat.com/security/cve/CVE-2023-50387
- bugzilla.suse.com/show_bug.cgi?id=1219823
- docs.powerdns.com/recursor/security-advisories/powerdns-advisory-2024-01.html
- gitlab.nic.cz/knot/knot-resolver/-/releases/v5.7.1
- kb.isc.org/docs/cve-2023-50387
- lists.debian.org/debian-lts-announce/2024/02/msg00006.html
- lists.debian.org/debian-lts-announce/2024/05/msg00011.html
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/6FV5O347JTX7P5OZA6NGO4MKTXRXMKOZ/
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BUIP7T7Z4T3UHLXFWG6XIVDP4GYPD3AI/
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/HVRDSJVZKMCXKKPP6PNR62T7RWZ3YSDZ/
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/IGSLGKUAQTW5JPPZCMF5YPEYALLRUZZ6/
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PNNHZSZPG2E7NBMBNYPGHCFI4V4XRWNQ/
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RGS7JN6FZXUSTC2XKQHH27574XOULYYJ/
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/SVYA42BLXUCIDLD35YIJPJSHDIADNYMP/
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TEXGOYGW7DBS3N2QSSQONZ4ENIRQEAPG/
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/UQESRWMJCF4JEYJEAKLRM6CT55GLJAB7/
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZDZFMEKQTZ4L7RY46FCENWFB5MDT263R/
- lists.thekelleys.org.uk/pipermail/dnsmasq-discuss/2024q1/017430.html
Vendor advisories and official records. Exploit/PoC links are deliberately left out.