CVE-2020-27737
No known exploitation. EPSS puts it in the 89th percentile. A vendor fix is available.
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.
- 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.
- Patch availablerecord updated
- Publishedweakness classified, att&ck mapped
Affected products
And 9 more affected products. See all after sign-in
Technical detail
CVSS 3.1 vector
Open in the CVSS calculatorCVSS: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
References in the record
- securitylab.ru/news/518760.php&
- cert-portal.siemens.com/productcert/pdf/ssa-669158.pdf&
- cybersecurity-help.cz/vdb/SB2021041407&
And 19 more references. See all after sign-in
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