CVE-2017-7500

Public on

Last Modified: UTC

Description

It was found that rpm did not properly handle RPM installations when a destination path was a symbolic link to a directory, possibly changing ownership and permissions of an arbitrary directory, and RPM files being placed in an arbitrary destination. An attacker, with write access to a directory in which a subdirectory will be installed, could redirect that directory to an arbitrary location and gain root privilege.

It was found that rpm did not properly handle RPM installations when a destination path was a symbolic link to a directory, possibly changing ownership and permissions of an arbitrary directory, and RPM files being placed in an arbitrary destination. An attacker, with write access to a directory in which a subdirectory will be installed, could redirect that directory to an arbitrary location and gain root privilege.

Statement

Red Hat Product Security has rated this issue as having Moderate security impact. This issue is not currently planned to be addressed in future updates. For additional information, refer to the Issue Severity Classification: https://access.redhat.com/security/updates/classification/.

Red Hat Product Security has rated this issue as having Moderate security impact. This issue is not currently planned to be addressed in future updates. For additional information, refer to the Issue Severity Classification: https://access.redhat.com/security/updates/classification/.

Additional information

  • Bugzilla 1450369: rpm: Following symlinks to directories when installing packages allows privilege escalation
  • CWE-59: Improper Link Resolution Before File Access ('Link Following')
  • FAQ: Frequently asked questions about CVE-2017-7500

Common Vulnerability Scoring System (CVSS) Score Details

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 HatNVD

CVSS v3 Base Score

7.3

7.8

Attack Vector

Local

Local

Attack Complexity

Low

Low

Privileges Required

Low

Low

User Interaction

Required

None

Scope

Unchanged

Unchanged

Confidentiality Impact

High

High

Integrity Impact

High

High

Availability Impact

High

High

CVSS v3 Vector

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

NVD: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Understanding the Weakness (CWE)

CWE-59

Confidentiality,Integrity,Access Control

Technical Impact: Read Files or Directories; Modify Files or Directories; Bypass Protection Mechanism

An attacker may be able to traverse the file system to unintended locations and read or overwrite the contents of unexpected files. If the files are used for a security mechanism then an attacker may be able to bypass the mechanism.

Other

Technical Impact: Execute Unauthorized Code or Commands

Windows simple shortcuts, sometimes referred to as soft links, can be exploited remotely since a ".LNK" file can be uploaded like a normal file. This can enable remote execution.

Acknowledgements

Red Hat would like to thank Ludwig Nussel (SUSE) for reporting this issue.

Frequently Asked Questions

Why is Red Hat's CVSS v3 score or Impact different from other vendors?

My product is listed as "Under investigation" or "Affected", when will Red Hat release a fix for this vulnerability?

What can I do if my product is listed as "Will not fix"?

What can I do if my product is listed as "Fix deferred"?

What is a mitigation?

I have a Red Hat product but it is not in the above list, is it affected?

Why is my security scanner reporting my product as vulnerable to this vulnerability even though my product version is fixed or not affected?

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