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01 Record

CVE-2019-3855

An integer overflow flaw which could lead to an out of bounds write was discovered in libssh2 before 1.8.1 in the way packets are read from the server. A remote attacker who compromises a SSH server

HighPUBLISHEDCNA: redhat
CNA base score7.5 CVSS v3.xCVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
View raw JSON

02 Description

An integer overflow flaw which could lead to an out of bounds write was discovered in libssh2 before 1.8.1 in the way packets are read from the server. A remote attacker who compromises a SSH server

03 Exploitation and scoring

Exploitation
Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.
SSVC decision
  • ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
  • AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
  • Technical ImpacttotalSuccessful exploitation gives total control of the vulnerable component.
CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.
EPSS probability
9.29% probability of exploitation activity in the next 30 days.
EPSS percentile
Equal to or higher than the score of 95.0% of scored records. A rank, not a probability.
NVD base score
8.8 (CVSS v3.x), scored by the NVD independently of the CNA.
NVD CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
NVD analysis status
Modified. NVD last modified this record on 2026-10-14.
Red Hat severity
Important. Red Hat's rating for its own products, not a CVSS rating.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

04 Metadata

Published
2019-03-21 20:13Z7 YR AGO
Last updated
2026-10-14 06:35Z15 DAYS AGO
Reserved
2019-01-03
Assigning CNA
redhat
Record state
PUBLISHED
Severity
High (CVSS 7.5)
CNA CVSS vector
CVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
Weaknesses
  • CWE-190Integer Overflow or WraparoundBase
  • CWE-787Out-of-bounds WriteBase
Data version
5.2
Document digest
451df32b9cdfae993aba0dcab341850c018901e29d2cb5dc5355dc2d00f0cedc

05 Affected products

VendorProductVersionsPlatforms
The libssh2 Projectlibssh21.8.1—

06 References

07 Fixed in

Arch Linux

  • libssh2
    Fixed in 1.8.1-1

Source: Arch Linux Security Tracker, the Arch Linux security team. Reformatted by exploit.cc.

Debian 12

  • libssh2
    Fixed in 1.8.0-2.1

Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.

Debian 13

  • libssh2
    Fixed in 1.8.0-2.1

Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.

Debian 14

  • libssh2
    Fixed in 1.8.0-2.1

Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu Pro 14.04 LTS

  • libssh2
    Fixed in 1.4.3-2ubuntu0.2+esm1
    Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu Pro 16.04 LTS

  • libssh2
    Fixed in 1.5.0-2ubuntu0.1+esm1
    Available with Ubuntu Pro: https://ubuntu.com/pro

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu Pro 18.04 LTS

  • libssh2
    No fix yet

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

A release or ecosystem missing from this list has no record here. It may be unaffected or not covered by the source. Source notices and licences.