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 domain name record decompression functionality does not properly validate the pointer offset values. The parsing of malformed responses could result in a read access 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.
An official patch is available. Apply the patch as soon as possible.
CVSS v4.0 Metrics
Exploitability
Attack VectorNetwork
ComplexityHigh
RequirementsPresent
PrivilegesNone
User InteractionNone
Threat
Exploit MaturityPoC
Vulnerable System
ConfidentialityLow
IntegrityNone
AvailabilityHigh
Subsequent System
ConfidentialityNone
IntegrityNone
AvailabilityNone
Supplemental
SafetyNegligible
AutomatableYes
RecoveryAutomatic
Value DensityConcentrated
UrgencyMedium
Patch StatusOfficial Patch
Change Log
| Date | Source | Changes | Score |
|---|
| 2026-07-21 | nvd | patch: Unavailable→Official Patch | 6.9 → 6.9 |
| 2026-07-21 | cve.org | initial, patch: Unavailable | 6.9 |
Affected Software
| Vendor | Product | Version |
|---|
| Siemens | APOGEE PXC Compact (BACnet) | < 3.5.5 |
| Siemens | APOGEE PXC Compact (P2 Ethernet) | < 2.8.20 |
| Siemens | APOGEE PXC Modular (BACnet) | < 3.5.5 |
| Siemens | APOGEE PXC Modular (P2 Ethernet) | < 2.8.20 |
| Siemens | Nucleus NET | All versions |
| Siemens | Nucleus ReadyStart V3 | < 2017.02.3 |
| Siemens | Nucleus ReadyStart V4 | < 4.1.0 |
| Siemens | Nucleus Source Code | Versions including affected DNS modules |
| siemens | nucleus_net | All versions |
| siemens | nucleus_readystart_v3 | < 2017.02.3 |
| siemens | nucleus_readystart_v4 | < 4.1.0 |
| siemens | nucleus_source_code | All versions |
| Siemens | SIMOTICS CONNECT 400 | < 0.5.0.0 |
| siemens | simotics_connect_400_firmware | ≥ 0.5.0.0 |
| Siemens | TALON TC Compact (BACnet) | < 3.5.5 |
| Siemens | TALON TC Modular (BACnet) | < 3.5.5 |
Published: 2021-04-22
