Buffer overflow in Lz4_project Lz4

CVE-2021-3520

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…

Vulnerability class: Integer Overflow

EPSS: 0.032 (86.6th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2021-3520?
CVE-2021-3520 is a critical-severity vulnerability in Lz4_project Lz4, classified under Integer Overflow or Wraparound. CVSS score: 9.8/10. Published 2021-06-02.
How severe is CVE-2021-3520?
Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2021-3520 known to be exploited?
3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.