CVE-2018-1050

Description

A null pointer dereference flaw was found in Samba RPC external printer service. An attacker could use this flaw to cause the printer spooler service to crash.

Mitigation

Ensure the paramter:
rpc_server:spoolss = external
is not set in the [global] section of your smb.conf.

Common Vulnerability Scoring System (CVSS) Score Details

Info alert:Important note

CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).

CVSS v3 Score Breakdown

Red HatNVDcve.org
Base Score4.34.3N/A
Attack VectorAdjacent NetworkAdjacent NetworkN/A
Attack ComplexityLowLowN/A
Privileges RequiredNoneNoneN/A
User InteractionNoneNoneN/A
ScopeUnchangedUnchangedN/A
ConfidentialityNoneNoneN/A
Integrity ImpactNoneNoneN/A
Availability ImpactLowLowN/A

Vector

Red Hat: CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

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

Understanding the Weakness (CWE)

Availability

Technical Impact: DoS: Crash, Exit, or Restart

NULL pointer dereferences usually result in the failure of the process unless exception handling (on some platforms) is available and implemented. Even when exception handling is being used, it can still be very difficult to return the software to a safe state of operation.

Integrity,Confidentiality

Technical Impact: Execute Unauthorized Code or Commands; Read Memory; Modify Memory

In rare circumstances, when NULL is equivalent to the 0x0 memory address and privileged code can access it, then writing or reading memory is possible, which may lead to code execution.

Acknowledgements

Red Hat would like to thank the Samba project for reporting this issue.

Frequently Asked Questions

Want to get errata notifications? Sign up here.