Libssh2 up to 1.8.0 _libssh2_packet_require/_libssh2_packet_requirev Packet out-of-bounds

CVSS Meta Temp Score
CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.
Current Exploit Price (≈)
Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.
CTI Interest Score
Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
7.0$0-$5k0.00

Summaryinfo

A vulnerability, which was classified as critical, has been found in Libssh2 up to 1.8.0. This issue affects the function _libssh2_packet_require/_libssh2_packet_requirev. The manipulation as part of Packet leads to out-of-bounds. This vulnerability is listed as CVE-2019-3859. The attack may be initiated remotely. There is no available exploit. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability was found in Libssh2 up to 1.8.0. It has been rated as critical. This issue affects the function _libssh2_packet_require/_libssh2_packet_requirev. The manipulation as part of a Packet leads to a out-of-bounds vulnerability. Using CWE to declare the problem leads to CWE-125. The product reads data past the end, or before the beginning, of the intended buffer. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

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.

The bug was discovered 03/18/2019. The weakness was presented 03/21/2019 by Chris Coulson as confirmed bug report (Bugzilla). The advisory is shared at bugzilla.redhat.com. The identification of this vulnerability is CVE-2019-3859 since 01/03/2019. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Technical details are known, but no exploit is available.

The vulnerability was handled as a non-public zero-day exploit for at least 3 days. During that time the estimated underground price was around $0-$5k. The vulnerability scanner Nessus provides a plugin with the ID 214139 (F5 Networks BIG-IP : libssh vulnerabilities (K000149288)), which helps to determine the existence of the flaw in a target environment. The commercial vulnerability scanner Qualys is able to test this issue with plugin 172157 (SUSE Enterprise Linux Security Update for libssh2_org (SUSE-SU-2019:13982-1)).

Upgrading to version 1.8.1 eliminates this vulnerability.

The vulnerability is also documented in the databases at Tenable (214139), EUVD (EUVD-2019-13473) and SecurityFocus (BID 107485†). See VDB-131994, VDB-132104, VDB-132105 and VDB-132210 for similar entries. Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Name

Version

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.1
VulDB Meta Temp Score: 7.0

VulDB Base Score: 7.3
VulDB Temp Score: 7.0
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 9.1
NVD Vector: 🔍

CNA Base Score: 5.0
CNA Vector (Red Hat, Inc.): 🔍

CVSSv2info

AVACAuCIA
💳💳💳💳💳💳
💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock

VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍

Exploitinginfo

Class: Out-of-bounds
CWE: CWE-125 / CWE-119
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

0-DayUnlockUnlockUnlockUnlock
TodayUnlockUnlockUnlockUnlock

Nessus ID: 214139
Nessus Name: F5 Networks BIG-IP : libssh vulnerabilities (K000149288)

Qualys ID: 🔍
Qualys Name: 🔍

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Upgrade: Libssh2 1.8.1

Timelineinfo

01/03/2019 🔍
03/18/2019 +74 days 🔍
03/18/2019 +0 days 🔍
03/21/2019 +3 days 🔍
03/22/2019 +1 days 🔍
12/18/2025 +2463 days 🔍

Sourcesinfo

Advisory: 152136
Researcher: Chris Coulson
Status: Confirmed
Confirmation: 🔍

CVE: CVE-2019-3859 (🔍)
GCVE (CVE): GCVE-0-2019-3859
GCVE (VulDB): GCVE-100-131993
EUVD: 🔍
SecurityFocus: 107485 - libssh2 Multiple Security Vulnerabilities

See also: 🔍

Entryinfo

Created: 03/22/2019 08:26
Updated: 12/18/2025 14:51
Changes: 03/22/2019 08:26 (64), 05/18/2020 12:30 (5), 08/03/2023 22:58 (4), 08/03/2023 23:11 (13), 01/15/2025 03:40 (17), 12/18/2025 13:13 (1), 12/18/2025 14:51 (1)
Complete: 🔍
Cache ID: 216::103

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Discussion

No comments yet. Languages: en.

Please log in to comment.

◂ PreviousOverviewNext ▸

Want to know what is going to be exploited?

We predict KEV entries!