The libssh2 Project Libssh2: Integer Overflow or Wraparound (CVE-2019-3863)
Published Last modified Sources: CVE.org
What is affected, what to do
A flaw was found in libssh2 before 1.8.1 creating a vulnerability on the SSH client side. A server could send a multiple keyboard interactive response messages whose total length are greater than unsigned char max characters.
Update libssh2 to version 1.8.1.
- Affected
- The libssh2 Project Libssh2
eq 1.8.1..1.8.1
- The libssh2 Project Libssh2
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Metrics
8.8
Priority
XIEM Effective CVSS: highest available CVSS rating from NVD and vendor data.
Source: NVD, CVSS v3
7.5
CVSS v3
Severity High on the scale from 0 to 10.
Source: CVE.org
3.4 %
EPSS score
Moderate — model estimates 1-10% exploitation likelihood.
Source: FIRST EPSS, percentile 88.9
Show all metrics
- Severity
- High
Priority (0–325)
The priority score is a consolidated metric that condenses several individual signals into a single, action-guiding ranking: technical severity (CVSS), exploitation likelihood (EPSS), known-exploited status (KEV) and the context of the affected asset. The aim is to answer the only truly important question in vulnerability management: what first?
Read in glossary- 100.77 Methodology
Exploit maturity
An exploit is code or a technique that specifically uses a concrete vulnerability to force unintended behaviour — such as executing code or escalating privileges. It is the tool that turns a theoretical flaw into a practical attack.
Read in glossary- no public PoC known
XIEM Effective CVSS
XIEM® is the tiered managed-security operating model from NEOSEC and a registered trademark of NEOSEC GmbH. It extends classic SIEM — the central collection, normalisation and correlation of security-relevant events — with endpoint forensics, network visibility and deception technology, and consolidates them into three building tiers: Sentry, Orchestrate and Command.
Read in glossary- 8.8 Methodology
CVSS v3
CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions.
Read in glossary- 7.5
EPSS score
The EPSS score is the absolute model output for an individual vulnerability: the estimated probability of real-world exploitation within the next 30 days, expressed as a value between 0 and 1 (i.e. 0 % to 100 %). A score of 0.42 means „the model estimates a 42 % chance of real-world exploitation within 30 days“.
Read in glossary- 3.4 %
- Moderate — model estimates 1-10% exploitation likelihood.
EPSS percentile
The EPSS percentile is the relative position of a vulnerability within all EPSS-scored CVEs, expressed as a value between 0 and 1. A percentile of 0.90 means „this CVE has a higher EPSS score than 90 % of all other scored CVEs“. Unlike the EPSS score, it is not a probability — but a positioning within a ranking.
Read in glossary- 88.9
- Critical — this CVE ranks in the top fifth of all CVEs scored today (rank ≥ 80%).
KEV status
The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching.
Read in glossary- —
- Published
- CISA assessment (SSVC)
- Exploitation: none known · not automatable · Technical impact: total
- Source: CISA Vulnrichment, as of 23 April 2025
CWE
CWE is a catalogue of typical weakness types in software and hardware — such as flawed input validation, unsafe memory handling or poor authentication. Where a CVE names a concrete vulnerability in a concrete product, a CWE describes the underlying class of defect.
Read in glossary- CWE-190, CWE-787
Detection rules
No NEOSEC detection rule is available for this vulnerability yet.
Classification under NIS2 and CRA
Rule-based classification from exploitation status and severity. It does not replace a case-by-case assessment.
NIS2
NIS2 is EU Directive (EU) 2022/2555 to raise the level of cybersecurity across the Union. It substantially broadens obligations compared with the first NIS directive: more sectors, mandatory risk management, staged reporting duties and personal accountability of senior management.
Read in glossary- High technical severity: assess and remediate the vulnerability in vulnerability handling under Art. 21(2)(e) NIS2 and document the decision.
CRA
The CRA is EU Regulation (EU) 2024/2847 setting horizontal cybersecurity requirements for „products with digital elements“ — from industrial controllers and software to connected consumer devices. For the first time manufacturers must ensure security across the entire product lifecycle, handle vulnerabilities and provide security updates.
Read in glossary- From 11.12.2027, Annex I Part II CRA requires manufacturers of affected products with digital elements to handle vulnerabilities without delay and provide security updates.
ISO/IEC 27001
ISO/IEC 27001 is the internationally leading standard for an information security management system (ISMS). It describes a risk-based, process-oriented framework to systematically plan, implement, review and improve information security.
Read in glossary- Control A.8.8, management of technical vulnerabilities: assess relevance to your systems, plan remediation and keep evidence.
Description
A flaw was found in libssh2 before 1.8.1 creating a vulnerability on the SSH client side. A server could send a multiple keyboard interactive response messages whose total length are greater than unsigned char max characters. This value is used by the SSH client as an index to copy memory causing in an out of bounds memory write error.
Source: cvelistv5, NVD (NIST)
Affected products
The following versions are affected. Older releases of the same product line are also vulnerable unless stated otherwise.
| Affected versions | Fixed in | ||
|---|---|---|---|
| The libssh2 Project | libssh2 |
|
|
| libssh2 | libssh2 |
|
|
| netapp | ontap_select_deploy_administration_utility |
|
|
Vendors and products
- Debian Debian Linux
- Libssh2 libssh2
- NetApp NetApp ONTAP Select Deploy administration utility
- openSUSE openSUSE Leap
- Red Hat Redhat Enterprise Linux Desktop
- Red Hat Redhat Enterprise Linux Server
- Red Hat Redhat Enterprise Linux Server Advanced mission critical Update Support (AUS)
- Red Hat Red Hat Enterprise Linux Server Extended Update Support (EUS)
- Red Hat Red Hat Enterprise Linux Server (TUS)
- Red Hat Red Hat Enterprise Linux Workstation
- The Libssh2 Project Libssh2
Affected operating systems
| Linux | debian | debian_linux | 8.0 |
| Linux | redhat | enterprise_linux_desktop | 7.0 |
| Linux | redhat | enterprise_linux_server | 7.0 |
| Linux | redhat | enterprise_linux_server_aus | 7.6 |
| Linux | redhat | enterprise_linux_server_eus | 7.6 |
| Linux | redhat | enterprise_linux_server_tus | 7.6 |
| Linux | redhat | enterprise_linux_workstation | 7.0 |
| Linux | opensuse | leap | 15.0 |
| Linux | opensuse | leap | 42.3 |
Weakness classes (CWE)
CWE-190Integer Overflow or Wraparound
Base
The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.
Entry at MITRE CWE-190CWE-787Out-of-bounds Write
Base
The product writes data past the end, or before the beginning, of the intended buffer.
Entry at MITRE CWE-787
References & sources
- bugzilla.redhat.comshow_bug.cgi?id=CVE-2019-3863x_refsource_CONFIRM
- libssh2.orgCVE-2019-3863.htmlx_refsource_MISC
- lists.debian.org[debian-lts-announce] 20190326 [SECURITY] [DLA 1730-1] libssh2 security updateMailing list, x_refsource_MLIST
- security.netapp.comadvisory/ntap-20190327-0005x_refsource_CONFIRM
- access.redhat.comRHSA-2019:0679Vendor advisory, x_refsource_REDHAT
- lists.opensuse.orgopenSUSE-SU-2019:1075Vendor advisory, x_refsource_SUSE
- lists.opensuse.orgopenSUSE-SU-2019:1109Vendor advisory, x_refsource_SUSE
- lists.fedoraproject.orgFEDORA-2019-3348cb4934Vendor advisory, x_refsource_FEDORA
- debian.orgDSA-4431Vendor advisory, x_refsource_DEBIAN
- seclists.org20190415 [SECURITY] [DSA 4431-1] libssh2 security updateMailing list, x_refsource_BUGTRAQ
- access.redhat.comRHSA-2019:1175Vendor advisory, x_refsource_REDHAT
- access.redhat.comRHSA-2019:1652Vendor advisory, x_refsource_REDHAT
- access.redhat.comRHSA-2019:1791Vendor advisory, x_refsource_REDHAT
- access.redhat.comRHSA-2019:1943Vendor advisory, x_refsource_REDHAT
- access.redhat.comRHSA-2019:2399Vendor advisory, x_refsource_REDHAT
- oracle.comtechnetwork/security-advisory/cpuoct2019-5072832.htmlx_refsource_MISC
- Siemens ProductCERTproductcert/html/ssa-398330.html
Changes to this CVE
Who changed this CVE and when: NVD (analysis, affected products, CVSS), the CVE publisher (CNA) and additional providers such as CISA (ADP).
Record modifiedRed Hat
Show 39 original changes
Individual changes of this event as published by NVD Type Action Before After Reference added —http://lists.opensuse.org/opensuse-security-announce/2019-03/msg00040.htmlReference added —http://lists.opensuse.org/opensuse-security-announce/2019-04/msg00003.htmlReference added —https://access.redhat.com/errata/RHSA-2019:0679Reference added —https://access.redhat.com/errata/RHSA-2019:1175Reference added —https://access.redhat.com/errata/RHSA-2019:1652Reference added —https://access.redhat.com/errata/RHSA-2019:1791Reference added —https://access.redhat.com/errata/RHSA-2019:1943Reference added —https://access.redhat.com/errata/RHSA-2019:2399Reference added —https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2019-3863Reference added —https://lists.debian.org/debian-lts-announce/2019/03/msg00032.htmlReference added —https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/5DK6VO2CEUTAJFYIKWNZKEKYMYR3NO2O/Reference added —https://seclists.org/bugtraq/2019/Apr/25Reference added —https://security.netapp.com/advisory/ntap-20190327-0005/Reference added —https://www.debian.org/security/2019/dsa-4431Reference added —https://www.libssh2.org/CVE-2019-3863.htmlReference added —https://www.oracle.com/technetwork/security-advisory/cpuoct2019-5072832.htmlReference removed http://lists.opensuse.org/opensuse-security-announce/2019-03/msg00040.html—Reference removed http://lists.opensuse.org/opensuse-security-announce/2019-04/msg00003.html—Reference removed https://access.redhat.com/errata/RHSA-2019:0679—Reference removed https://access.redhat.com/errata/RHSA-2019:1175—Reference removed https://access.redhat.com/errata/RHSA-2019:1652—Reference removed https://access.redhat.com/errata/RHSA-2019:1791—Reference removed https://access.redhat.com/errata/RHSA-2019:1943—Reference removed https://access.redhat.com/errata/RHSA-2019:2399—Reference removed https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2019-3863—Reference removed https://lists.debian.org/debian-lts-announce/2019/03/msg00032.html—Reference removed https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/5DK6VO2CEUTAJFYIKWNZKEKYMYR3NO2O/—Reference removed https://seclists.org/bugtraq/2019/Apr/25—Reference removed https://security.netapp.com/advisory/ntap-20190327-0005/—Reference removed https://www.debian.org/security/2019/dsa-4431—Reference removed https://www.libssh2.org/CVE-2019-3863.html—Reference removed https://www.oracle.com/technetwork/security-advisory/cpuoct2019-5072832.html—Reference type removed http://lists.opensuse.org/opensuse-security-announce/2019-03/msg00040.html Types: Mailing List, Third Party Advisory—Reference type removed http://lists.opensuse.org/opensuse-security-announce/2019-04/msg00003.html Types: Third Party Advisory—Reference type removed https://access.redhat.com/errata/RHSA-2019:0679 Types: Third Party Advisory—Reference type removed https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2019-3863 Types: Issue Tracking, Patch, Third Party Advisory—Reference type removed https://lists.debian.org/debian-lts-announce/2019/03/msg00032.html Types: Mailing List, Third Party Advisory—Reference type removed https://security.netapp.com/advisory/ntap-20190327-0005/ Types: Third Party Advisory—Reference type removed https://www.libssh2.org/CVE-2019-3863.html Types: Patch, Vendor Advisory—Source identifier: secalert@redhat.com
Record modifiedCVE Program
Show 39 original changes
Individual changes of this event as published by NVD Type Action Before After Reference added —http://lists.opensuse.org/opensuse-security-announce/2019-03/msg00040.htmlReference added —http://lists.opensuse.org/opensuse-security-announce/2019-04/msg00003.htmlReference added —https://access.redhat.com/errata/RHSA-2019:0679Reference added —https://access.redhat.com/errata/RHSA-2019:1175Reference added —https://access.redhat.com/errata/RHSA-2019:1652Reference added —https://access.redhat.com/errata/RHSA-2019:1791Reference added —https://access.redhat.com/errata/RHSA-2019:1943Reference added —https://access.redhat.com/errata/RHSA-2019:2399Reference added —https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2019-3863Reference added —https://lists.debian.org/debian-lts-announce/2019/03/msg00032.htmlReference added —https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/5DK6VO2CEUTAJFYIKWNZKEKYMYR3NO2O/Reference added —https://seclists.org/bugtraq/2019/Apr/25Reference added —https://security.netapp.com/advisory/ntap-20190327-0005/Reference added —https://www.debian.org/security/2019/dsa-4431Reference added —https://www.libssh2.org/CVE-2019-3863.htmlReference added —https://www.oracle.com/technetwork/security-advisory/cpuoct2019-5072832.htmlReference removed http://lists.opensuse.org/opensuse-security-announce/2019-03/msg00040.html—Reference removed http://lists.opensuse.org/opensuse-security-announce/2019-04/msg00003.html—Reference removed https://access.redhat.com/errata/RHSA-2019:0679—Reference removed https://access.redhat.com/errata/RHSA-2019:1175—Reference removed https://access.redhat.com/errata/RHSA-2019:1652—Reference removed https://access.redhat.com/errata/RHSA-2019:1791—Reference removed https://access.redhat.com/errata/RHSA-2019:1943—Reference removed https://access.redhat.com/errata/RHSA-2019:2399—Reference removed https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2019-3863—Reference removed https://lists.debian.org/debian-lts-announce/2019/03/msg00032.html—Reference removed https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/5DK6VO2CEUTAJFYIKWNZKEKYMYR3NO2O/—Reference removed https://seclists.org/bugtraq/2019/Apr/25—Reference removed https://security.netapp.com/advisory/ntap-20190327-0005/—Reference removed https://www.debian.org/security/2019/dsa-4431—Reference removed https://www.libssh2.org/CVE-2019-3863.html—Reference removed https://www.oracle.com/technetwork/security-advisory/cpuoct2019-5072832.html—Reference type removed http://lists.opensuse.org/opensuse-security-announce/2019-03/msg00040.html Types: Mailing List, Third Party Advisory—Reference type removed http://lists.opensuse.org/opensuse-security-announce/2019-04/msg00003.html Types: Third Party Advisory—Reference type removed https://access.redhat.com/errata/RHSA-2019:0679 Types: Third Party Advisory—Reference type removed https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2019-3863 Types: Issue Tracking, Patch, Third Party Advisory—Reference type removed https://lists.debian.org/debian-lts-announce/2019/03/msg00032.html Types: Mailing List, Third Party Advisory—Reference type removed https://security.netapp.com/advisory/ntap-20190327-0005/ Types: Third Party Advisory—Reference type removed https://www.libssh2.org/CVE-2019-3863.html Types: Patch, Vendor Advisory—Source identifier: af854a3a-2127-422b-91ae-364da2661108
Record modifiedSiemens ADP
Show 2 original changes
Individual changes of this event as published by NVD Type Action Before After Affected versions (publisher) added —New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2019/3xxx/CVE-2019-3863.json">CVE-2019-3863</a>Reference added —https://cert-portal.siemens.com/productcert/html/ssa-398330.htmlSource identifier: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
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