CVE Tools

CVE-2020-27737

No known exploitation. EPSS puts it in the 89th percentile. A vendor fix is available.

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

What to do

The vendor has published a fix. Version details are below where the sources state them.

  • Siemens SIMOTICS CONNECT 400Affected: All versions < V0.5.0.0Upgrade to: not statedStated by: CVE record
  • Siemens Nucleus ReadyStart V3Affected: All versions < V2017.02.3Upgrade to: not statedStated by: CVE record
  • Siemens Nucleus ReadyStart V4Affected: All versions < V4.1.0Upgrade to: not statedStated by: CVE record
  • Siemens APOGEE PXC CompactAffected: All versions < V3.5.5Upgrade to: not statedStated by: CVE record
  • Siemens APOGEE PXC CompactAffected: All versions < V2.8.20Upgrade to: not statedStated by: CVE record

Versions as the sources state them. 7 more products have version data. Full version matrix after sign-in

What it is

From the CVE record

A vulnerability has been identified in APOGEE PXC Compact (BACnet) (All versions < V3.5.5), APOGEE PXC Compact (P2 Ethernet) (All versions < V2.8.20), APOGEE PXC Modular (BACnet) (All versions < V3.5.5), APOGEE PXC Modular (P2 Ethernet) (All versions < V2.8.20), Nucleus NET (All versions), Nucleus ReadyStart V3 (All versions < V2017.02.3), Nucleus ReadyStart V4 (All versions < V4.1.0), Nucleus Source Code (Versions including affected DNS modules), SIMOTICS CONNECT 400 (All versions < V0.5.0.0), TALON TC Compact (BACnet) (All versions < V3.5.5), TALON TC Modular (BACnet) (All versions < V3.5.5). The DNS response parsing functionality does not properly validate various length and counts of the records. The parsing of malformed responses could result in a read past the end of an allocated structure. An attacker with a privileged position in the network could leverage this vulnerability to cause a denial-of-service condition or leak the memory past the allocated structure.

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.

EPSS89th
CISA KEV

Not in the catalog. CISA has not confirmed exploitation.

Public exploits

No public exploit or proof of concept found in the sources we track.

EPSS

3.6% chance of exploitation activity in the next 30 days, which ranks it in the 89th percentile of scored CVEs.

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

Lifecycle

5 events over 1309 days, from the signal feeds we watch.

  1. Patch availablerecord updated
  2. Publishedweakness classified, att&ck mapped

Affected products

Technical detail

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

Scored 6.5 by NVD.

How it is reached

  • Attack Vector NetworkExploitable remotely over the network without any special conditions
  • Attack Complexity HighRequires specific conditions like a race condition or non-default configuration
  • Privileges Required NoneNo authentication required — anyone can exploit this
  • User Interaction NoneNo user interaction needed — fully automated exploitation

Scope

  • Scope UnchangedImpact is limited to the vulnerable component itself

Impact if exploited

  • Confidentiality LowSome restricted information is disclosed, but limited in scope
  • Integrity NoneNo integrity impact
  • 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

Watch the software you run.

My Stack ranks new CVEs for your products by real-world exploitation, so the next serious one reaches you without reading every advisory.

We'll flag the next CVE, public exploit or patch for SIMOTICS CONNECT 400, not every advisory.