UBUNTU-CVE-2025-59089

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Source
https://ubuntu.com/security/CVE-2025-59089
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2025/UBUNTU-CVE-2025-59089.json
JSON Data
https://api.osv.dev/v1/vulns/UBUNTU-CVE-2025-59089
Upstream
Published
2025-11-12T17:15:00Z
Modified
2026-01-20T18:51:01.292487Z
Severity
  • 5.9 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
  • Ubuntu - medium
Summary
[none]
Details

If an attacker causes kdcproxy to connect to an attacker-controlled KDC server (e.g. through server-side request forgery), they can exploit the fact that kdcproxy does not enforce bounds on TCP response length to conduct a denial-of-service attack. While receiving the KDC's response, kdcproxy copies the entire buffered stream into a new buffer on each recv() call, even when the transfer is incomplete, causing excessive memory allocation and CPU usage. Additionally, kdcproxy accepts incoming response chunks as long as the received data length is not exactly equal to the length indicated in the response header, even when individual chunks or the total buffer exceed the maximum length of a Kerberos message. This allows an attacker to send unbounded data until the connection timeout is reached (approximately 12 seconds), exhausting server memory or CPU resources. Multiple concurrent requests can cause accept queue overflow, denying service to legitimate clients.

References

Affected packages

Ubuntu:16.04:LTS
python-kdcproxy

Package

Name
python-kdcproxy
Purl
pkg:deb/ubuntu/python-kdcproxy@0.3.2-1?arch=source&distro=xenial

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

0.*
0.3.2-1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "python-kdcproxy",
            "binary_version": "0.3.2-1"
        },
        {
            "binary_name": "python3-kdcproxy",
            "binary_version": "0.3.2-1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2025/UBUNTU-CVE-2025-59089.json"
Ubuntu:18.04:LTS
python-kdcproxy

Package

Name
python-kdcproxy
Purl
pkg:deb/ubuntu/python-kdcproxy@0.3.2-5?arch=source&distro=bionic

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

0.*
0.3.2-5

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "python-kdcproxy",
            "binary_version": "0.3.2-5"
        },
        {
            "binary_name": "python3-kdcproxy",
            "binary_version": "0.3.2-5"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2025/UBUNTU-CVE-2025-59089.json"
Ubuntu:20.04:LTS
python-kdcproxy

Package

Name
python-kdcproxy
Purl
pkg:deb/ubuntu/python-kdcproxy@0.4.2-1?arch=source&distro=focal

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

0.*
0.4-1
0.4.2-1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "python3-kdcproxy",
            "binary_version": "0.4.2-1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2025/UBUNTU-CVE-2025-59089.json"
Ubuntu:22.04:LTS
python-kdcproxy

Package

Name
python-kdcproxy
Purl
pkg:deb/ubuntu/python-kdcproxy@1.0.0-1?arch=source&distro=jammy

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

1.*
1.0.0-1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "python3-kdcproxy",
            "binary_version": "1.0.0-1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2025/UBUNTU-CVE-2025-59089.json"
Ubuntu:24.04:LTS
python-kdcproxy

Package

Name
python-kdcproxy
Purl
pkg:deb/ubuntu/python-kdcproxy@1.0.0-2?arch=source&distro=noble

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

1.*
1.0.0-1
1.0.0-2

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "python3-kdcproxy",
            "binary_version": "1.0.0-2"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2025/UBUNTU-CVE-2025-59089.json"
Ubuntu:25.10
python-kdcproxy

Package

Name
python-kdcproxy
Purl
pkg:deb/ubuntu/python-kdcproxy@1.0.0-2?arch=source&distro=questing

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

1.*
1.0.0-2

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "python3-kdcproxy",
            "binary_version": "1.0.0-2"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2025/UBUNTU-CVE-2025-59089.json"