CVE-2021-3520

Lz4 vulnerability

CVSS

9.8

EPSS

3.2%

EPSS pct

87th

Exploited

No known

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.

Affected vendor

Lz4 Project

Affected product

Lz4

CVSS vector

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

Weakness type (CWE)

CWE-190 — Integer Overflow or Wraparound
CWE-787 — Out-of-bounds Write

Published

2021-06-02

Risk analysis

Based on its CVSS vector, this vulnerability is exploitable over the network, low attack complexity, requiring no privileges, no user interaction. Successful exploitation leads to high impact to confidentiality, high impact to integrity, high impact to availability.

Its EPSS score of 3.2% reflects a lower probability of exploitation activity in the wild over the next 30 days, placing it above 87% of all scored CVEs.

Check your external exposure to CVE-2021-3520

Confirm whether Lz4 Project Lz4 is running on any internet-facing host or subdomain.
Match discovered service fingerprints against the version affected by CVE-2021-3520.
Prioritise remediation if the asset is public, business-critical, or near authentication/payment flows.

How ThreatPort helps with CVE-2021-3520

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