Vulnerability · Published Apr 22, 2021 · Assigned by siemens
CVE-2020-27736
Medium 6.5
In plain English
A medium-severity security flaw in APOGEE PXC Compact (BACnet) from Siemens. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 3.6% (higher than 89% of all known vulnerabilities).
Official description
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 label parsing functionality does not properly validate the null-terminated name in DNS-responses. 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 read memory.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Siemens | APOGEE PXC Compact (BACnet) | All versions < V3.5.5 |
| Siemens | APOGEE PXC Compact (P2 Ethernet) | All versions < V2.8.20 |
| Siemens | APOGEE PXC Modular (BACnet) | All versions < V3.5.5 |
| Siemens | APOGEE PXC Modular (P2 Ethernet) | All versions < V2.8.20 |
| Siemens | Nucleus NET | All versions |
| Siemens | Nucleus ReadyStart V3 | All versions < V2017.02.3 |
| Siemens | Nucleus ReadyStart V4 | All versions < V4.1.0 |
| Siemens | Nucleus Source Code | Versions including affected DNS modules |
| Siemens | SIMOTICS CONNECT 400 | All versions < V0.5.0.0 |
| Siemens | TALON TC Compact (BACnet) | All versions < V3.5.5 |
| Siemens | TALON TC Modular (BACnet) | All versions < V3.5.5 |
Weakness: CWE-170 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:H/E:P/RL:O/RC:C