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NVD / CVE Program· CNA apache

CVE-2023-44981: Apache ZooKeeper: Authorization bypass in SASL Quorum Peer Authentication

CriticalCVSS 9.1 · v3.1—No exploit Fix available

Noroxi assessment

Priority: Monitor (action score 37/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 2.2% (FIRST EPSS); higher than 82.9% 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: Apache Software Foundation Apache ZooKeeper 3.7.0, 3.9.1.

Low priority for now. Upgrade to Apache Software Foundation Apache ZooKeeper 3.7.0, 3.9.1 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

Authorization Bypass Through User-Controlled Key vulnerability in Apache ZooKeeper. If SASL Quorum Peer authentication is enabled in ZooKeeper (quorum.auth.enableSasl=true), the authorization is done by verifying that the instance part in SASL authentication ID is listed in zoo.cfg server list. The instance part in SASL auth ID is optional and if it's missing, like 'eve@EXAMPLE.COM', the authorization check will be skipped. As a result an arbitrary endpoint could join the cluster and begin propagating counterfeit changes to the leader, essentially giving it complete read-write access to the data tree. Quorum Peer authentication is not enabled by default. Users are recommended to upgrade to version 3.9.1, 3.8.3, 3.7.2, which fixes the issue. Alternately ensure the ensemble election/quorum communication is protected by a firewall as this will mitigate the issue. See the documentation for more details on correct cluster administration.

Published
Oct 11, 2023
Updated
Jun 17, 2026
EPSS
2.2% · 82th percentile

Report tools

JSON

Action score

37

Monitor

Low priority for now.

CVSS
36 / 40 · 9.1 / 10
CISA KEV
0 / 30 · Not listed
EPSS
1 / 30 · 2.2%

CISA SSVC decision

Exploitation
none
Automatable
yes
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2023-44981

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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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.

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Affected 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.

VendorProduct
apachezookeeper
debiandebian linux

Versions reported by the vendor

Affected version ranges reported by the assigning authority (apache). Independent of NVD's CPE analysis and usually ahead of it.

  • Apache Software Foundation Apache ZooKeeper

    • 3.9.0 and later · before 3.9.1affected · maven
    • 3.8.0 and later · up to and including 3.8.2affected · maven
    • 3.7.0 and later · up to and including 3.7.1affected · maven
    • before 3.7.0affected · maven
Affected versions · NVD (6)

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • apache zookeeperbefore 3.7.2
  • apache zookeeper3.8.0 and later · before 3.8.3
  • apache zookeeper3.9.0
  • debian debian linux10.0
  • debian debian linux11.0
  • debian debian linux12.0

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:10zookeeperbefore 3.4.13-2+deb10u13.4.13-2+deb10u1
Debian:11zookeeperbefore 3.4.13-6+deb11u13.4.13-6+deb11u1
Debian:12zookeeperbefore 3.8.0-11+deb12u13.8.0-11+deb12u1
Debian:13zookeeperbefore 3.9.1-13.9.1-1
Mavenorg.apache.zookeeper:zookeeperfrom 3.8.0 · before 3.8.33.8.3
Mavenorg.apache.zookeeper:zookeeperfrom 3.9.0 · before 3.9.13.9.1
Mavenorg.apache.zookeeper:zookeeperbefore 3.7.23.7.2

Same product

apache: all records

Other highest-scoring records for the same primary product.

  • CVE-2017-5637Two four letter word commands "wchp/wchc" are CPU intensive and could cause spike of CPU utilization on Apache ZooKeeper server if abused…
    52Plan
  • CVE-2024-51504Apache ZooKeeper: Authentication bypass with IP-based authentication in Admin Server
    36Monitor
  • CVE-2016-5017Buffer overflow in the C cli shell in Apache Zookeeper before 3.4.9 and 3.5.x before 3.5.3, when using the "cmd:" batch mode syntax, allows…
    34Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2018-8012May 21, 2018 · No authentication/authorization is enforced when a server attempts to join a quorum in Apache ZooKeeper before 3.4.10, and 3.5.0-alpha…
    33Monitor
  • Later →CVE-2024-23944Mar 15, 2024 · Apache ZooKeeper: Information disclosure in persistent watcher handling
    21Monitor
  • Later →CVE-2025-58457Sep 24, 2025 · Apache ZooKeeper: Insufficient Permission Check in AdminServer Snapshot/Restore Commands
    17Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Apache Software Foundation Apache ZooKeeper3.7.0Vendor (CNA)
Apache Software Foundation Apache ZooKeeper3.9.1Vendor (CNA)
debian:zookeeper3.8.0-11+deb12u1 · Debian:12Package registry (OSV)
Maven:org.apache.zookeeper:zookeeper3.7.2Package registry (OSV)
Maven:org.apache.zookeeper:zookeeper3.8.3Package registry (OSV)
Maven:org.apache.zookeeper:zookeeper3.9.1Package 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.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

Not on record for this CVE: EPSS history · patch commit or PR link · variant or chain candidate · public bounty program.

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
high · data can be read
Integrity
high · data or configuration can be modified
Availability
none
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
None

Weakness class (CWE)

CWE-639 · Authorization Bypass Through User-Controlled Key

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

nvd-primary

Root cause

The endpoint fetches the record by the ID sent in the request, but never checks whether the record belongs to the requesting user.

The bug in code

The whole CWE-639 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

ts
const invoice = await Invoice.findById(req.params.id);res.json(invoice);

Fixed

ts
const invoice = await Invoice.findOne({  id: req.params.id,  ownerId: req.user.id,});if (!invoice) return res.sendStatus(404);res.json(invoice);

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

References

Show all references (4 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records