CVE Tools
Sign in

CVE-2021-27391

A vulnerability has been identified in APOGEE MBC (PPC) (P2 Ethernet) (All versions >= V2.6.3), APOGEE MEC (PPC) (P2 Ethernet) (All versions >= V2.6.3), APOGEE PXC Compact (BACnet) (All versions < ...

Published: Sep 14, 2021Updated: Apr 23, 2025 Sources: CVE List NVD BDU csafCWE-120
9.8CRITICAL
NVD MITRE
EPSS Score
3.4%
Top 12.0%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
Patch Available
Self-Check
Not available

Description

A buffer overflow vulnerability in the integrated web server of multiple APOGEE and TALON automation devices could allow a remote attacker to execute arbitrary code on the devices with root privileges. Affected devices include the APOGEE MBC/MEC/PXC P2 Ethernet devices with Power Open Processors (PPC), APOGEE PXC BACnet devices, and TALON TC BACnet devices. Siemens has released updates for several affected products and recommends to update to the latest versions. Siemens recommends countermeasures for products where updates are not, or not yet available.

No summary for this CVE yet.

CVSS Vector Breakdown

AV:NAC:LPR:NUI:NS:UC:HI:HA:H
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:NPrivileges Required
None
UI:NUser Interaction
None
Scope
S:UScope
Unchanged
Impact
C:HConfidentiality
High
I:HIntegrity
High
A:HAvailability
High
Open in CVSS calculator →

Weaknesses

CWE-120

Affected Products

Siemens AG
commercial·DEaka Siemens
APOGEE MBC (PPC) (P2 Ethernet)
ICS / OT / IoT
APOGEE MEC (PPC) (P2 Ethernet)
ICS / OT / IoT
APOGEE PXC Compact (BACnet)
ICS / OT / IoT
APOGEE PXC Compact (P2 Ethernet)
ICS / OT / IoT
APOGEE PXC Modular (BACnet)
ICS / OT / IoT
APOGEE PXC Modular (P2 Ethernet)
ICS / OT / IoT
TALON TC Compact (BACnet)
ICS / OT / IoT
TALON TC Modular (BACnet)
ICS / OT / IoT
and 16 more affected products View all →

Exploitability

Official Patch Available
Is your org exposed to CVE-2021-27391?We can run the check for you — a free external exposure review, no install. Check my exposure

Attack Graph

Products CVE Techniques Tactics

Click technique nodes for MITRE ATT&CK details · drag to pan · Ctrl/⌘ + scroll to zoom, or go fullscreen.

MITRE ATT&CK

2 techniques
Initial Access
Privilege Escalation
View detailed technique mapping

References

https://cert-portal.siemens.com/productcert/csaf/ssa-944498.json
cert-portal.siemens.com
https://cert-portal.siemens.com/productcert/txt/ssa-944498.txt
cert-portal.siemens.com
https://cert-portal.siemens.com/productcert/pdf/ssa-944498.pdf
cert-portal.siemens.com
and 12 more references View all →

Unlock Complete Vulnerability Intelligence

Get the full picture for CVE-2021-27391 and every CVE in our database. Create a free account — no credit card required.

Create Free Account
Plain-language analysis
Impact assessment and exploitation scenario in plain English
Attack graph visualization
Interactive attack path and kill chain mapping
Exploit details & PoC links
ExploitDB, Metasploit, GitHub PoCs with direct links
Nuclei scanner templates
Ready-to-use vulnerability scanner templates
Full remediation guide
Patch instructions, workarounds, and compliance impact
Interactive AI chat
Ask questions about this vulnerability in natural language
Related vulnerabilities
Semantically similar CVEs and attack patterns
REST API & MCP access
Integrate vulnerability data into your workflows