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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 serve...

Public exploit available. Not confirmed exploited in the wild yet. Fixed versions are out.

CVSS 3.18.8HighEPSS percentile95th9.3% chance in 30 daysCISA KEVNot listedNo confirmed exploitation
Public exploit: 1 sourceFix5 products2 fixed builds listed below

Published Updated Sources: CVE.org, NVD, BDU, CSAF

NVD CVE.org

What to do

Find your product and version, then upgrade to the build on the right.

  • The libssh2 Project libssh2Affected: 1.8.1Upgrade to: not statedStated by: CVE record
  • Libssh2Affected: < 1.8.1Upgrade to: 1.8.1Stated by: NVD
  • Apple XcodeAffected: < 11.0Upgrade to: 11.0Stated by: NVD
  • Red Hat Inc. Red Hat Enterprise LinuxAffected: Server 6Upgrade to: not statedStated by: BDU
  • Сообщество свободного программного обеспечения Debian GNU/LinuxAffected: 9Upgrade to: not statedStated by: BDU

Versions as the sources state them. 5 more products have version data. Full version matrix after sign-in

Check it yourselfA free OpenVAS check exists for this CVE. Run it against your hosts.Is your organisation exposed?Request an assessment to establish which checks fit your systems.

What it is

From the CVE record

Multiple vulnerabilities have been identified in the additional GNU/Linux subsystem of the firmware version >= V3.1.0 and < V3.1.5 for the SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP (incl. SIPLUS variant). These GNU/Linux vulnerabilities have been externally identified. Siemens has released new versions for the affected products and recommends to update to the latest versions. Note: This SSA advises vulnerabilities for firmware version V3.1 only; for versions < V3.1 refer to Siemens Security Bulletin SSB-439005 ( https://cert-portal.siemens.com/productcert/html/ssb-439005.html).

In plain language

No plain-language summary for this CVE yet.

Exploitation

Where each signal puts this CVE on the scale from published to confirmed exploited.

EPSS95th
Public exploit
CISA KEV

Not in the catalog. CISA has not confirmed exploitation.

Public exploits

1 source with a proof of concept or module.

Exploit links, PoCs and Metasploit modules after sign-in
EPSS

9.3% chance of exploitation activity in the next 30 days, which ranks it in the 95th percentile of scored CVEs.

Exploit Prediction Scoring System, FIRST.org. A probability, not a confirmation.

Lifecycle

The patch came 471 days before any public exploit.

  1. Patch availablerecord updated
  2. OpenVAS check added
  3. EPSS band changemoderate → low
  4. Public exploit / PoCsource: packetstorm
  5. Patch availablerecord updated
  6. Publishedweakness classified, att&ck mapped

Affected products

And 14 more affected products. See all after sign-in

Technical detail

CVSS 3.1 vector

Open in the CVSS calculator

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Scored 8.8 by NVD.

How it is reached

  • Attack Vector NetworkExploitable remotely over the network without any special conditions
  • Attack Complexity LowNo special conditions — the attack can be reliably reproduced
  • Privileges Required NoneNo authentication required — anyone can exploit this
  • User Interaction RequiredA user must click a link, open a file, or perform some action

Scope

  • Scope UnchangedImpact is limited to the vulnerable component itself

Impact if exploited

  • Confidentiality HighTotal information disclosure — all data in the component is compromised
  • Integrity HighTotal loss of integrity — attacker can modify any data in the component
  • Availability HighTotal denial of service — the component is completely unavailable

Weaknesses

ATT&CK techniques

Mapped from the weaknesses above (CWE to ATT&CK), not observed in attacks.

Sources

References in the record

And 40 more references. See all after sign-in

In the news

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We'll flag the next CVE, public exploit or patch for Debian GNU/Linux, not every advisory. This one: public exploit.