CVE-2019-3855

Publication date 21 March 2019

Last updated 18 August 2025

Ubuntu priority

Medium

Why this priority?

Cvss 3 Severity Score

7.5 · High

Score breakdown

Description

An integer overflow flaw which could lead to an out of bounds write was discovered in libssh2 before 1.8.1 in the way packets are read from the server. A remote attacker who compromises a SSH server may be able to execute code on the client system when a user connects to the server.

From the Ubuntu Security Team

It was discovered that libssh2 mishandled certain input. If libssh2 were used to connect to a malicious or compromised SSH server, a remote, unauthenticated attacker could execute arbitrary code on the client system.

Status

Package Ubuntu Release Status
libssh2 25.10 questing
Not affected
25.04 plucky
Not affected
24.10 oracular
Not affected
24.04 LTS noble
Not affected
23.10 mantic
Not affected
23.04 lunar
Not affected
22.10 kinetic
Not affected
22.04 LTS jammy
Not affected
21.10 impish
Not affected
21.04 hirsute
Not affected
20.10 groovy
Not affected
20.04 LTS focal
Not affected
19.10 eoan
Not affected
19.04 disco
Not affected
18.10 cosmic Ignored end of life
18.04 LTS bionic
Vulnerable
16.04 LTS xenial
Fixed 1.5.0-2ubuntu0.1+esm1
14.04 LTS trusty
Fixed 1.4.3-2ubuntu0.2+esm1

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Severity score breakdown

Parameter Value
Base score 7.5 · High
Attack vector Network
Attack complexity High
Privileges required None
User interaction Required
Scope Unchanged
Confidentiality High
Integrity impact High
Availability impact High
Vector CVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H

References

Related Ubuntu Security Notices (USN)

Other references