---
id: CVE-2020-6096
title: >-
  An exploitable signed comparison vulnerability exists in the ARMv7 memcpy()
  implementation of GNU glibc 2.30.9000
summary: >-
  An exploitable signed comparison vulnerability exists in the ARMv7 memcpy()
  implementation of GNU glibc 2.30.9000. Calling memcpy() (on ARMv7 targets that
  utilize the GNU glibc implementation) with a negative value for the 'num'
  paramete…
severity: high
cvss: 8.1
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-195
  - CWE-191
  - CWE-681
vendor: gnu
product: glibc
affected:
  - glibc <= 2.31
  - fedora = 31
  - fedora = 32
  - debian_linux = 10.0
published: '2020-04-01'
updated: '2026-10-14'
sourceUpdated: '2026-10-14T09:17:19.140'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2020-6096'
references:
  - url: >-
      https://lists.apache.org/thread.html/rf9fa47ab66495c78bb4120b0754dd9531ca2ff0430f6685ac9b07772%40%3Cdev.mina.apache.org%3E
    label: talos-cna@cisco.com
  - url: 'https://lists.debian.org/debian-lts-announce/2022/10/msg00021.html'
    label: talos-cna@cisco.com
  - url: >-
      https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/SPYXTDOOB4PQGTYAMZAZNJIB3FF6YQXI/
    label: talos-cna@cisco.com
  - url: >-
      https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/URXOIA2LDUKHQXK4BE55BQBRI6ZZG3Y6/
    label: talos-cna@cisco.com
  - url: 'https://security.gentoo.org/glsa/202101-20'
    label: talos-cna@cisco.com
  - url: 'https://sourceware.org/bugzilla/show_bug.cgi?id=25620'
    label: talos-cna@cisco.com
  - url: 'https://www.talosintelligence.com/vulnerability_reports/TALOS-2020-1019'
    label: talos-cna@cisco.com
  - url: >-
      https://lists.apache.org/thread.html/rf9fa47ab66495c78bb4120b0754dd9531ca2ff0430f6685ac9b07772%40%3Cdev.mina.apache.org%3E
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://lists.debian.org/debian-lts-announce/2022/10/msg00021.html'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/SPYXTDOOB4PQGTYAMZAZNJIB3FF6YQXI/
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/URXOIA2LDUKHQXK4BE55BQBRI6ZZG3Y6/
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://security.gentoo.org/glsa/202101-20'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://sourceware.org/bugzilla/show_bug.cgi?id=25620'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://www.talosintelligence.com/vulnerability_reports/TALOS-2020-1019'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://cert-portal.siemens.com/productcert/html/ssa-398330.html'
    label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
tags:
  - nvd
epss: 0.05354
epssPercentile: 0.92471
ingestedAt: '2026-10-14T09:24:26.054Z'
---

## Overview

An exploitable signed comparison vulnerability exists in the ARMv7 memcpy() implementation of GNU glibc 2.30.9000. Calling memcpy() (on ARMv7 targets that utilize the GNU glibc implementation) with a negative value for the 'num' parameter results in a signed comparison vulnerability. If an attacker underflows the 'num' parameter to memcpy(), this vulnerability could lead to undefined behavior such as writing to out-of-bounds memory and potentially remote code execution. Furthermore, this memcpy() implementation allows for program execution to continue in scenarios where a segmentation fault or crash should have occurred. The dangers occur in that subsequent execution and iterations of this code will be executed with this corrupted data.

## Affected

- `glibc <= 2.31`
- `fedora = 31`
- `fedora = 32`
- `debian_linux = 10.0`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.