CVE-2018-1057
Description
A flaw was found in the way Samba AD DC validated user permissions. An authenticated attacker could use this flaw to change any other users passwords, including administrative users.
Statement
The versions of samba shipped with Red Hat Enterprise Linux 6 and 7 do not support Active Directory Domain Controller (AD-DC) mode. Therefore this flaw does not affect Red Hat Enterprise Linux 6 and 7.
Mitigation
Revoke the change passwords right for everyone from all user objects (including computers) in the directory. Note that this will prevent users from being able to change their own expired passwords, so the maximum password age should be set to a value that prevents user passwords from expiring while the workaround is in place. For more information please refer to: https://bugzilla.redhat.com/show_bug.cgi?id=1553553#c3
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).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 7.4 | 8.8 | N/A |
| Attack Vector | Adjacent Network | Network | N/A |
| Attack Complexity | Low | Low | N/A |
| Privileges Required | Low | Low | N/A |
| User Interaction | Required | None | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality | High | High | N/A |
| Integrity Impact | High | High | N/A |
| Availability Impact | High | High | N/A |
Vector
Red Hat: CVSS:3.0/AV:A/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H
NVD: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Understanding the Weakness (CWE)
Confidentiality
Technical Impact: Read Application Data; Read Files or Directories
An attacker could bypass intended access restrictions to read sensitive data, either by reading the data directly from a data store that is not correctly restricted, or by accessing insufficiently-protected, privileged functionality to read the data.
Integrity
Technical Impact: Modify Application Data; Modify Files or Directories
An attacker could bypass intended access restrictions to modify sensitive data, either by writing the data directly to a data store that is not correctly restricted, or by accessing insufficiently-protected, privileged functionality to write the data.
Access Control
Technical Impact: Gain Privileges or Assume Identity; Bypass Protection Mechanism
An attacker could bypass intended access restrictions to gain privileges by modifying or reading critical data directly, or by accessing privileged functionality.
Confidentiality,Integrity,Availability
Technical Impact: Execute Unauthorized Code or Commands
An attacker could use elevated privileges to execute unauthorized commands or code.
Availability
Technical Impact: DoS: Crash, Exit, or Restart; DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory); DoS: Resource Consumption (Other)
An attacker could gain unauthorized access to resources on the system and excessively consume those resources, leading to a denial of service.
Acknowledgements
Red Hat would like to thank the Samba project for reporting this issue. Upstream acknowledges Björn Baumbach (Sernet) as the original reporter.
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