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Enterprise LinuxOperating system · Redhat

CVE-2015-0240

HIGH · 10.0 CVSS v2.0 Published 2015-02-24
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
100/100
Remediation priority · Urgent
High EPSS Public exploit Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
The Netlogon server implementation in smbd in Samba 3.5.x and 3.6.x before 3.6.25, 4.0.x before 4.0.25, 4.1.x before 4.1.17, and 4.2.x before 4.2.0rc5 performs a free operation on an uninitialized stack pointer, which allows remote attackers to execute arbitrary code via crafted Netlogon packets that use the ServerPasswordSet RPC API, as demonstrated by packets reaching the _netr_ServerPasswordSet function in rpc_server/netlogon/srv_netlog_nt.c.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Samba's Netlogon server (smbd) contains a critical memory corruption vulnerability where a free() operation is performed on an uninitialized stack pointer. Remote attackers can exploit this by sending specially crafted Netlogon RPC packets using the ServerPasswordSet API, achieving arbitrary code execution with the privileges of the smbd process.

MitigationApply the vendor patches for Samba versions 3.5.x, 3.6.x, 4.0.x, 4.1.x, and 4.2.x as specified in the official advisory. If patching is immediately impossible, restrict access to Netlogon RPC endpoints (TCP ports 445/139) from untrusted networks.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Enterprise LinuxOperating system
Affected:= 5= 6.0= 7.0
Ubuntu LinuxOperating system
Affected:= 12.04= 14.04= 14.10
SambaApplication
Affected:= 3.5.0= 3.5.1= 3.5.2= 3.5.3= 3.5.4= 3.5.5= 3.5.6= 3.5.7= 3.5.8= 3.5.9= 3.5.10= 3.5.11
Suse Linux Enterprise DesktopOperating system
Affected:= 12
Suse Linux Enterprise ServerOperating system
Affected:= 12
Suse Linux Enterprise Software Development KitOperating system
Affected:= 12

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Authentication
None
Confidentiality
Complete
Integrity
Complete
Availability
Complete

AV:N/AC:L/Au:N/C:C/I:C/A:C

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify installed Samba version
    Run 'smbd --version' or check package manager: 'rpm -q samba' (RHEL/CentOS) or 'dpkg -l samba' (Ubuntu/Debian)
    Affected if Version is 3.5.0 through 3.5.11, or falls within the unpatched 3.5.x, 3.6.x, 4.0.x, 4.1.x, or 4.2.x series
  2. Verify smbd process is running
    Run 'ps aux | grep smbd' or 'systemctl status smbd' (or 'smbd' service name depending on OS)
    Affected if smbd is actively running - the vulnerability resides in this daemon
  3. Confirm Netlogon RPC endpoint accessibility
    Check if ports 445 (SMB over TCP) or 139 (NetBIOS) are listening: 'netstat -tlnp | grep -E ':(139|445)' or 'ss -tlnp | grep -E ':(139|445)'
    Affected if Ports 139/445 are open and accepting connections - this is the attack vector for the ServerPasswordSet API
  4. Check Netlogon configuration in smb.conf
    Examine /etc/samba/smb.conf for 'netlogon' share definition and 'security' mode settings: 'testparm -s 2>/dev/null | grep -i netlogon'
    Affected if A 'netlogon' share is defined and the server is configured for domain controller or active directory membership, enabling Netlogon RPC handling

You are affected if Samba version 3.5.0-3.5.11 (or unpatched 3.5.x/3.6.x/4.0.x/4.1.x/4.2.x) is installed with smbd running and Netlogon RPC ports (139/445) are accessible on the network.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply the vendor patches for Samba versions 3.5.x, 3.6.x, 4.0.x, 4.1.x, and 4.2.x as specified in the official advisory. If patching is immediately impossible, restrict access to Netlogon RPC endpoints (TCP ports 445/139) from untrusted networks.

Recommended fix High confidence

Samba 3.6.25+ (for 3.5.x/3.6.x branches), 4.0.25+ (for 4.0.x), 4.1.17+ (for 4.1.x), or 4.2.0+ (for 4.2.x)

  1. 1. Identify current Samba version: rpm -q samba or dpkg -l | grep samba
  2. 2. For Samba 3.5.x/3.6.x: upgrade to Samba 3.6.25 or later
  3. 3. For Samba 4.0.x: upgrade to Samba 4.0.25 or later
  4. 4. For Samba 4.1.x: upgrade to Samba 4.1.17 or later
  5. 5. For Samba 4.2.x: upgrade to Samba 4.2.0rc5 or later (preferably 4.2.0 final or newer)
  6. 6. After upgrade, restart the smbd service: systemctl restart smb (or service smb restart on older systems)
  7. 7. Verify the new version is installed: smbd --version
  8. 8. Ensure Netlogon service is properly configured and listening
Caveat Upgrading Samba may affect existing share configurations, authentication settings, or compatibility with older Windows clients; review release notes before upgrading

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Enterprise Linux Scoped from the published advisory
  • Consultation4.0 h
  • Implementation6.0 h
  • Testing8.0 h
  • Review / QA4.0 h
22.0 hours of engineering $3,800
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2015-0240 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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