Libssh
CVE-2016-0739
MEDIUM
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A01:2025 - Broken Access Control
ASVS 5.0
V14 - Data Protection Data exposure prevention
MITRE ATT&CK
2 techniques across 2 tactics: Collection, Discovery The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
| Impact | CVSS score of 5.9 (MEDIUM). Attack characteristics: network attack vector, high complexity, no privileges required, no user interaction not required. EPSS exploitation probability: 4.31%. |
| Exploit ScenarioDerived | A remote attacker could access sensitive data that should not be disclosed by sending crafted requests to the affected application. No authentication is required to exploit this vulnerability. |
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Alert meAnalysisAI
libssh before 0.7.3 improperly truncates ephemeral secrets generated for the (1) diffie-hellman-group1 and (2) diffie-hellman-group14 key exchange methods to 128 bits, which makes it easier for. Rated medium severity (CVSS 5.9), this vulnerability is remotely exploitable, no authentication required. No vendor patch available.
RemediationAI
No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Minimize information in error messages, implement proper access controls, encrypt sensitive data at rest and in transit.
Affects your stack
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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 Exposure of Sensitive Information (CWE-200), which allows attackers to access sensitive data that should not be disclosed. libssh before 0.7.3 improperly truncates ephemeral secrets generated for the (1) diffie-hellman-group1 and (2) diffie-hellman-group14 key exchange methods to 128 bits, which makes it easier for man-in-the-middle attackers to decrypt or intercept SSH sessions via unspecified vectors, aka a "bits/bytes confusion bug." Affected products include: Redhat Enterprise Linux, Canonical Ubuntu Linux, Libssh, Fedoraproject Fedora, Debian Debian Linux. Version information: before 0.7.3.
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- Exploit and PoC references, threat intelligence from 22 sources
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Severity by source
AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
DescriptionCVE.org
libssh before 0.7.3 improperly truncates ephemeral secrets generated for the (1) diffie-hellman-group1 and (2) diffie-hellman-group14 key exchange methods to 128 bits, which makes it easier for man-in-the-middle attackers to decrypt or intercept SSH sessions via unspecified vectors, aka a "bits/bytes confusion bug."
Threat Intelligence Overview
NVD
CVE.org
EPSS
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
Information disclosure occurs when an application unintentionally exposes sensitive data that aids attackers in reconnaissance or directly compromises security.
Affected Products (CPE)CVE.org
The SSH transport protocol with certain OpenSSH extensions, found in OpenSSH before 9.6 and other products, allows remot
A vulnerability was found in libssh's server-side state machine before versions 0.7.6 and 0.8.4. Rated critical severity
libssh 0.9.4 has a NULL pointer dereference in tftpserver.c if ssh_buffer_new returns NULL. Rated medium severity (CVSS
Multiple integer overflows in libssh before 0.5.3 allow remote attackers to cause a denial of service (infinite loop or
Multiple buffer overflows in libssh before 0.5.3 allow remote attackers to cause a denial of service (crash) or possibly
Cryptographic key derivation failure in libssh versions prior to 0.11.2 (when built against OpenSSL older than 3.0) can
A flaw was found with the libssh API function ssh_scp_new() in versions before 0.9.3 and before 0.8.8. Rated high severi
A flaw was found in libssh when using the ChaCha20 cipher with the OpenSSL library.
The (1) SSH_MSG_NEWKEYS and (2) SSH_MSG_KEXDH_REPLY packet handlers in package_cb.c in libssh before 0.6.5 do not proper
Double free vulnerability in the sftp_mkdir function in sftp.c in libssh before 0.5.3 allows remote attackers to cause a
Multiple double free vulnerabilities in the (1) agent_sign_data function in agent.c, (2) channel_request function in cha
Stack-based buffer overflow in libssh's SFTP server allows a connected client to crash the server or potentially execute
GitHub PoC
Exploit-DB