CVE-2021-3520
9.8 · CRITICALOverview
CVE-2021-3520 is a critical-severity vulnerability affecting lz4_project lz4. It was published on June 2, 2021 and has a CVSS 3.1 base score of 9.8 (CRITICAL).
This vulnerability has a CVSS 3.1 base score of 9.8, rated CRITICAL. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
Technical Description
There's a flaw in lz4. An attacker who submits a crafted file to an application linked with lz4 may be able to trigger an integer overflow, leading to calling of memmove() on a negative size argument, causing an out-of-bounds write and/or a crash. The greatest impact of this flaw is to availability, with some potential impact to confidentiality and integrity as well.
Remediation
Check the references section for vendor advisories and patches from lz4_project. Update lz4 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 |
|---|---|---|---|
| lz4_project | lz4 | >= 1.8.3, < 1.9.4 | Affected |
| splunk | universal_forwarder | >= 8.2.0, < 8.2.12 | Affected |
References
Frequently Asked Questions
What is CVE-2021-3520?
CVE-2021-3520 is a critical-severity vulnerability affecting lz4_project lz4. It was published on June 2, 2021 and has a CVSS 3.1 base score of 9.8 (CRITICAL).
How severe is CVE-2021-3520?
This vulnerability has a CVSS 3.1 base score of 9.8, rated CRITICAL. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
How do I fix or remediate CVE-2021-3520?
Check the references section for vendor advisories and patches from lz4_project. Update lz4 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-2021-3520?
CyberStrike's AI-powered security agents can automatically detect CVE-2021-3520 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 CRITICAL CVEs from 2021
View all →An issue was discovered in the Quiz and Survey Master plugin before 7.0.1 for WordPress. It made it
An issue was discovered in the Ultimate Member plugin before 2.1.12 for WordPress, aka Unauthenticat
An issue was discovered in the Ultimate Member plugin before 2.1.12 for WordPress, aka Unauthenticat
Dell Wyse ThinOS 8.6 and prior versions contain an insecure default configuration vulnerability. A r
Dell Wyse ThinOS 8.6 and prior versions contain an insecure default configuration vulnerability. A r
DELL EMC Avamar Server, versions 19.1, 19.2, 19.3, contain a SQL Injection Vulnerability in Fitness
DELL EMC Avamar Server, versions 19.1, 19.2, 19.3, contain an OS Command Injection Vulnerability in
An improper check for unusual or exceptional conditions in Juniper Networks Junos OS and Junos OS Ev
OneDev is an all-in-one devops platform. In OneDev before version 4.0.3, a Kubernetes REST endpoint
OneDev is an all-in-one devops platform. In OneDev before version 4.0.3, There is a vulnerability th
OneDev is an all-in-one devops platform. In OneDev before version 4.0.3, there is a critical vulnera
OneDev is an all-in-one devops platform. In OneDev before version 4.0.3, AttachmentUploadServlet als