Out-of-bounds Read in Libssh2

CVE-2019-3859

An out of bounds read flaw was discovered in libssh2 before 1.8.1 in the _libssh2_packet_require and _libssh2_packet_requirev functions. A remote attacker who compromises a SSH server may be able to cause a Denial of Service or read data in the client memory.

Vulnerability class: Buffer Overflow

EPSS: 0.063 (92.8th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2019-3859?
CVE-2019-3859 is a critical-severity vulnerability in Libssh2, classified under Out-of-bounds Read. CVSS score: 9.1/10. Published 2019-03-21.
How severe is CVE-2019-3859?
Critical severity. CVSS v3 base score is 9.1 out of 10.
Is CVE-2019-3859 known to be exploited?
6 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.