CVE-2021-47451
7.8 · HIGHOverview
CVE-2021-47451 is a high-severity vulnerability affecting linux linux_kernel. It was published on May 22, 2024 and has a CVSS 3.1 base score of 7.8 (HIGH).
This vulnerability has a CVSS 3.1 base score of 7.8, rated HIGH. It requires local or adjacent network access to exploit. Some level of privileges is required for exploitation.
Technical Description
In the Linux kernel, the following vulnerability has been resolved:
netfilter: xt_IDLETIMER: fix panic that occurs when timer_type has garbage value
Currently, when the rule related to IDLETIMER is added, idletimer_tg timer
structure is initialized by kmalloc on executing idletimer_tg_create
function. However, in this process timer->timer_type is not defined to
a specific value. Thus, timer->timer_type has garbage value and it occurs
kernel panic. So, this commit fixes the panic by initializing
timer->timer_type using kzalloc instead of kmalloc.
Test commands:
# iptables -A OUTPUT -j IDLETIMER --timeout 1 --label test
$ cat /sys/class/xt_idletimer/timers/test
Killed
Splat looks like:
BUG: KASAN: user-memory-access in alarm_expires_remaining+0x49/0x70
Read of size 8 at addr 0000002e8c7bc4c8 by task cat/917
CPU: 12 PID: 917 Comm: cat Not tainted 5.14.0+ #3 79940a339f71eb14fc81aee1757a20d5bf13eb0e
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1
Remediation
Check the references section for vendor advisories and patches from linux. Update linux_kernel to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| linux | linux_kernel | >= 5.7, < 5.10.76 | Affected |
References
Frequently Asked Questions
What is CVE-2021-47451?
CVE-2021-47451 is a high-severity vulnerability affecting linux linux_kernel. It was published on May 22, 2024 and has a CVSS 3.1 base score of 7.8 (HIGH).
How severe is CVE-2021-47451?
This vulnerability has a CVSS 3.1 base score of 7.8, rated HIGH. It requires local or adjacent network access to exploit. Some level of privileges is required for exploitation.
How do I fix or remediate CVE-2021-47451?
Check the references section for vendor advisories and patches from linux. Update linux_kernel to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2021-47451?
CyberStrike's AI-powered security agents can automatically detect CVE-2021-47451 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
How CyberStrike Helps
AI agents map your attack surface to find vulnerabilities like this one.
Automated penetration testing that runs continuously, not just quarterly.
AI-driven PR review catches vulnerable dependencies before they ship.
Browser-based exploitation validates findings with real proof-of-concept.
Related HIGH CVEs from 2021
View all →systeminformation is an open source system and OS information library for node.js. A command injecti
An Improper Access Control Privilege Escalation Vulnerability was discovered in the User Setting of
An SQL injection Privilege Escalation Vulnerability was discovered in the Orion Platform reported by
Insecure deserialization leading to Remote Code Execution was detected in the Orion Platform version
Insecure Deserialization of untrusted data remote code execution vulnerability was discovered in Pat
Deserialization of Untrusted Data in the Web Console Chart Endpoint can lead to remote code executio
Insecure Deseralization of untrusted data remote code execution vulnerability was discovered in Patc
SAP Web Dispatcher versions - 7.49, 7.53, 7.77, 7.81, KRNL64NUC - 7.22, 7.22EXT, 7.49, KRNL64UC -7.2
uploader.php in the KCFinder integration project through 2018-06-01 for Drupal mishandles validation
An issue was discovered in the PageLayer plugin before 1.1.2 for WordPress. The pagelayer_settings_p
MK-AUTH through 19.01 K4.9 allows CSRF for password changes via the central/executar_central.php?aca
IBM Cloud Pak System 2.3 is vulnerable to cross-site request forgery which could allow an attacker t