CVE-2021-31881 Denial of service in Capital Embedded AR Classic 431-422
A missing length validation in the DHCP client allows attackers to cause a Denial-of-Service condition in Siemens Capital Embedded AR Classic devices.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2021-31881?
CVE-2021-31881 is a high-severity denial of service vulnerability in Siemens Capital Embedded AR Classic 431-422, published on 9 Nov 2021. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
A vulnerability has been identified in Capital Embedded AR Classic 431-422 (All versions), Capital Embedded AR Classic R20-11 (All versions < V2303). When processing a DHCP OFFER message, the DHCP client application does not validate the length of the Vendor option(s), leading to Denial-of-Service conditions. (FSMD-2021-0008)
Weakness: CWE-125
Which versions are affected by CVE-2021-31881?
It affects 10 products.
Products include Siemens Apogee Modular Building Controller Firmware, Siemens Apogee Modular Equiment Controller Firmware, Siemens Apogee Pxc Compact Firmware, Siemens Apogee Pxc Modular Firmware, Siemens Capital Vstar, Siemens Nucleus Net and 4 more.
How do I fix CVE-2021-31881?
No fix has been published for CVE-2021-31881 yet. Limit exposure of the affected software until one is available.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2021-31881 being exploited?
There is no known exploitation of CVE-2021-31881 in the wild and no public exploit code.
Other vulnerabilities in Siemens Capital Embedded AR Classic 431-422
- CVE-2021-31884 Memory corruption in APOGEE MBC (PPC) (BACnet)
- CVE-2021-31886 Memory corruption in APOGEE MBC (PPC) (BACnet)
- CVE-2021-31887 Memory corruption in APOGEE MBC (PPC) (BACnet)
- CVE-2021-31888 Memory corruption in APOGEE MBC (PPC) (BACnet)
- CVE-2022-38371 Denial of service in APOGEE MBC (PPC) (BACnet)
Sources
Also known as GHSA-x327-px9p-wgr2.