HOME VULNERABILITIESCVE-2019-3859

CRITICAL

CVE-2019-3859

CWE-125Published: March 21, 2019· Updated: Jun 17, 2026

9.1

CVSS v3.1

Official Description

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.

Technical Analysis

CVE-2019-3859 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), availability disruption (denial of service), with a CVSS base score of 9.1.

CVSS v3.1 Vector Breakdown

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges Req.None

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityHigh

IntegrityNone

AvailabilityHigh

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

Affected Vendors & Products

Debian1 product(s)

debian linux

Fedora1 product(s)

fedora

libssh21 product(s)

libssh2

netapp1 product(s)

ontap select deploy administration utility

openSUSE1 product(s)

leap

Source: NVD CPE · 8 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time

Offensive Security exploit database

GitHub PoC Search

Community PoC repositories

Rapid7 / Metasploit

Metasploit module search

Security advisories & exploits

Official NIST entry

CVE Program entry

External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

PATCHhttp://packetstormsecurity.com/files/152136/Slackware-Security-Advisory-libssh2-Updates.html

PATCHhttp://www.openwall.com/lists/oss-security/2019/03/18/3

PATCHhttps://bugzilla.redhat.com/show_bug.cgi?id=CVE-2019-3859

PATCHhttps://seclists.org/bugtraq/2019/Mar/25

PATCHhttp://packetstormsecurity.com/files/152136/Slackware-Security-Advisory-libssh2-Updates.html

PATCHhttp://www.openwall.com/lists/oss-security/2019/03/18/3

PATCHhttps://bugzilla.redhat.com/show_bug.cgi?id=CVE-2019-3859

PATCHhttps://seclists.org/bugtraq/2019/Mar/25

ADVISORYhttp://lists.opensuse.org/opensuse-security-announce/2019-03/msg00040.html

ADVISORYhttp://lists.opensuse.org/opensuse-security-announce/2019-04/msg00003.html

ADVISORYhttp://lists.opensuse.org/opensuse-security-announce/2019-04/msg00102.html

ADVISORYhttp://lists.opensuse.org/opensuse-security-announce/2019-04/msg00103.html

ADVISORYhttp://www.securityfocus.com/bid/107485

ADVISORYhttps://lists.debian.org/debian-lts-announce/2019/03/msg00032.html

ADVISORYhttps://lists.debian.org/debian-lts-announce/2019/04/msg00006.html

ADVISORYhttps://seclists.org/bugtraq/2019/Apr/25

ADVISORYhttps://security.netapp.com/advisory/ntap-20190327-0005/

ADVISORYhttps://www.broadcom.com/support/fibre-channel-networking/security-advisories/brocade-security-advisory-2019-767

ADVISORYhttps://www.debian.org/security/2019/dsa-4431

ADVISORYhttps://www.libssh2.org/CVE-2019-3859.html

ADVISORYhttp://lists.opensuse.org/opensuse-security-announce/2019-03/msg00040.html

ADVISORYhttp://lists.opensuse.org/opensuse-security-announce/2019-04/msg00003.html

ADVISORYhttp://lists.opensuse.org/opensuse-security-announce/2019-04/msg00102.html

ADVISORYhttp://lists.opensuse.org/opensuse-security-announce/2019-04/msg00103.html

ADVISORYhttp://www.securityfocus.com/bid/107485

ADVISORYhttps://lists.debian.org/debian-lts-announce/2019/03/msg00032.html

ADVISORYhttps://lists.debian.org/debian-lts-announce/2019/04/msg00006.html

ADVISORYhttps://seclists.org/bugtraq/2019/Apr/25

ADVISORYhttps://security.netapp.com/advisory/ntap-20190327-0005/

ADVISORYhttps://www.broadcom.com/support/fibre-channel-networking/security-advisories/brocade-security-advisory-2019-767

ADVISORYhttps://www.debian.org/security/2019/dsa-4431

ADVISORYhttps://www.libssh2.org/CVE-2019-3859.html

All References (40)

→

http://lists.opensuse.org/opensuse-security-announce/2019-03/msg00040.htmlMailing List · Third Party Advisory

→

http://lists.opensuse.org/opensuse-security-announce/2019-04/msg00003.htmlMailing List · Third Party Advisory

→

http://lists.opensuse.org/opensuse-security-announce/2019-04/msg00102.htmlMailing List · Third Party Advisory

→

http://lists.opensuse.org/opensuse-security-announce/2019-04/msg00103.htmlMailing List · Third Party Advisory

→

http://packetstormsecurity.com/files/152136/Slackware-Security-Advisory-libssh2-Updates.htmlPatch · Third Party Advisory · VDB Entry

→

http://www.openwall.com/lists/oss-security/2019/03/18/3Mailing List · Patch · Third Party Advisory

→

http://www.securityfocus.com/bid/107485Third Party Advisory · VDB Entry

→

https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2019-3859Issue Tracking · Patch · Third Party Advisory

→

https://lists.debian.org/debian-lts-announce/2019/03/msg00032.htmlMailing List · Third Party Advisory

→

https://lists.debian.org/debian-lts-announce/2019/04/msg00006.htmlMailing List · Third Party Advisory

→

https://lists.debian.org/debian-lts-announce/2019/07/msg00024.html

→

https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/5DK6VO2CEUTAJFYIKWNZKEKYMYR3NO2O/

→

https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/XCWEA5ZCLKRDUK62QVVYMFWLWKOPX3LO/

→

https://seclists.org/bugtraq/2019/Apr/25Mailing List · Third Party Advisory

→

https://seclists.org/bugtraq/2019/Mar/25Mailing List · Patch · Third Party Advisory

Quick Facts

CVE IDCVE-2019-3859

CVSS Score9.1 / 10

SeverityCRITICAL

WeaknessCWE-125

CISA KEVNo

Affected5 vendor(s)

PublishedMar 21, 2019

Related CVEs (CWE-125)

Recommended Actions

→Apply vendor patches immediately
→Monitor CVE-2019-3859 in threat intel feeds
→Review IDS/IPS signatures for exploitation attempts

Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWatch. CVE data is provided under the NVD usage policy.

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