Libssh2
CVE-2019-3861
CRITICAL
Vulnerability Assessment
| Weakness |
CWE
ASVS 5.0
V15 - Secure Coding and Architecture Bounds checking, read limits
MITRE ATT&CK
1 technique across 1 tactic: Collection The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
| Impact | CVSS score of 9.1 (CRITICAL). Attack characteristics: network attack vector, low complexity, no privileges required, no user interaction not required. |
| Exploit ScenarioDerived | A remote attacker could read data from memory outside the intended buffer boundaries by sending crafted requests to the affected application. No authentication is required to exploit this vulnerability. |
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Alert meAnalysisAI
An out of bounds read flaw was discovered in libssh2 before 1.8.1 in the way SSH packets with a padding length value greater than the packet length are parsed. Rated critical severity (CVSS 9.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. This Out-of-bounds Read vulnerability could allow attackers to read data from memory outside the intended buffer boundaries.
RemediationAI
A vendor patch is available. Apply the latest security update as soon as possible. Validate array indices and buffer lengths. Use memory-safe languages. Enable AddressSanitizer during testing.
Affects your stack
Find out whether the stacks and servers you run are on an affected version.
Checking this CVE against your own stacks and servers is part of the Basic plan and up.
Technical ContextAI · show details
This vulnerability is classified as Out-of-bounds Read (CWE-125), which allows attackers to read data from memory outside the intended buffer boundaries. An out of bounds read flaw was discovered in libssh2 before 1.8.1 in the way SSH packets with a padding length value greater than the packet length are parsed. A remote attacker who compromises a SSH server may be able to cause a Denial of Service or read data in the client memory. Affected products include: Libssh2, Debian Debian Linux, Netapp Ontap Select Deploy Administration Utility, Opensuse Leap. Version information: before 1.8.1.
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- Exploit and PoC references, threat intelligence from 22 sources
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Severity by source
AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
DescriptionNVD
An out of bounds read flaw was discovered in libssh2 before 1.8.1 in the way SSH packets with a padding length value greater than the packet length are parsed. A remote attacker who compromises a SSH server may be able to cause a Denial of Service or read data in the client memory.
Threat Intelligence Overview
NVD
CVE.org
EPSS
VulDB
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
A buffer overflow occurs when a program writes more data to a memory buffer than it was allocated to hold, causing the excess data to spill into adjacent memory regions.
Information disclosure occurs when an application unintentionally exposes sensitive data that aids attackers in reconnaissance or directly compromises security.
Denial of Service attacks render applications or systems unavailable by overwhelming resources or triggering failure conditions.
Affected Products (CPE)NVD
The SSH transport protocol with certain OpenSSH extensions, found in OpenSSH before 9.6 and other products, allows remot
Remote code execution in libssh2 through version 1.11.1 stems from an unchecked packet_length field in ssh2_transport_re
In libssh2 v1.9.0 and earlier versions, the SSH_MSG_DISCONNECT logic in packet.c has an integer overflow in a bounds che
Heap buffer overflow in the libssh2 SSH client library (all versions through 1.11.1) lets a malicious or compromised SSH
Free of an uninitialized, attacker-influenceable pointer in libssh2 through 1.11.1 allows a malicious SSH server to corr
Out-of-bounds heap read in libssh2 through 1.11.1 enables a malicious SFTP server or man-in-the-middle attacker to leak
In libssh2 before 1.9.0, kex_method_diffie_hellman_group_exchange_sha256_key_exchange in kex.c has an integer overflow t
An out of bounds read flaw was discovered in libssh2 before 1.8.1 in the way SSH_MSG_CHANNEL_REQUEST packets with an exi
An integer overflow flaw which could lead to an out of bounds write was discovered in libssh2 before 1.8.1 in the way pa
An out of bounds read flaw was discovered in libssh2 before 1.8.1 when a specially crafted SFTP packet is received from
An out of bounds read flaw was discovered in libssh2 before 1.8.1 in the _libssh2_packet_require and _libssh2_packet_req
An out of bounds read flaw was discovered in libssh2 before 1.8.1 in the way SFTP packets with empty payloads are parsed
GitHub PoC
Exploit-DB