CVE-2017-18206

Description

A buffer overflow flaw was found in the zsh shell symbolic link resolver. A local, unprivileged user can create a specially crafted directory path which leads to a buffer overflow in the context of the user trying to do a symbolic link resolution in the aforementioned path. If the user affected is privileged, this leads to privilege escalation.

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 Score7.59.8N/A
Attack VectorLocalNetworkN/A
Attack ComplexityHighLowN/A
Privileges RequiredLowNoneN/A
User InteractionRequiredNoneN/A
ScopeChangedUnchangedN/A
ConfidentialityHighHighN/A
Integrity ImpactHighHighN/A
Availability ImpactHighHighN/A

Vector

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

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

Understanding the Weakness (CWE)

CWE-120

Integrity,Confidentiality,Availability

Technical Impact: Modify Memory; Execute Unauthorized Code or Commands

Buffer overflows often can be used to execute arbitrary code, which is usually outside the scope of the product's implicit security policy. This can often be used to subvert any other security service.

Availability

Technical Impact: Modify Memory; DoS: Crash, Exit, or Restart; DoS: Resource Consumption (CPU)

Buffer overflows generally lead to crashes. Other attacks leading to lack of availability are possible, including putting the product into an infinite loop.

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