CVE-2021-3984

Description

A flaw was found in vim. A possible heap-based buffer overflow allows an attacker to input a specially crafted file, leading to a crash or code execution. The highest threat from this vulnerability is confidentiality, integrity, and system availability.

Mitigation

Do not run untrusted vim scripts with -s {scriptin} as it is never safe to do so.

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 Score7.37.87.3
Attack VectorLocalLocalLocal
Attack ComplexityLowLowLow
Privileges RequiredNoneNoneNone
User InteractionRequiredRequiredRequired
ScopeUnchangedUnchangedUnchanged
ConfidentialityLowHighLow
Integrity ImpactHighHighHigh
Availability ImpactHighHighHigh

Vector

Red Hat: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:H/A:H

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

cve.org: CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:H/A:H

Understanding the Weakness (CWE)

Availability

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

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

Integrity,Confidentiality,Availability,Access Control

Technical Impact: Execute Unauthorized Code or Commands; Bypass Protection Mechanism; Modify Memory

Buffer overflows often can be used to execute arbitrary code, which is usually outside the scope of a program's implicit security policy. Besides important user data, heap-based overflows can be used to overwrite function pointers that may be living in memory, pointing it to the attacker's code. Even in applications that do not explicitly use function pointers, the run-time will usually leave many in memory. For example, object methods in C++ are generally implemented using function pointers. Even in C programs, there is often a global offset table used by the underlying runtime.

Integrity,Confidentiality,Availability,Access Control,Other

Technical Impact: Execute Unauthorized Code or Commands; Bypass Protection Mechanism; Other

When the consequence is arbitrary code execution, this can often be used to subvert any other security service.

Frequently Asked Questions

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