CVE-2019-17543
CWE-787Published: October 14, 2019· Updated: Jun 17, 2026
Official Description
LZ4 before 1.9.2 has a heap-based buffer overflow in LZ4_write32 (related to LZ4_compress_destSize), affecting applications that call LZ4_compress_fast with a large input. (This issue can also lead to data corruption.) NOTE: the vendor states "only a few specific / uncommon usages of the API are at risk."
Technical Analysis
CVE-2019-17543 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.
The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.
A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 8.1.
From a weakness classification perspective (CWE-787): Out-of-bounds write vulnerabilities can lead to data corruption, crashes, or arbitrary code execution.
CVSS v3.1 Vector Breakdown
Affected Vendors & Products
Exploit & PoC Resources
Official Patches & Advisories
All References (38)
Quick Facts
Related CVEs (CWE-787)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2019-17543 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts