CVE-2021-31884 Memory corruption in APOGEE MBC (PPC) (BACnet)
A DHCP client flaw in Siemens building automation systems allows out-of-bounds reads and writes, potentially causing denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2021-31884?
CVE-2021-31884 is a critical memory corruption vulnerability in Siemens APOGEE MBC (PPC) (BACnet), published on 9 Nov 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
A vulnerability has been identified in APOGEE MBC (PPC) (BACnet) (All versions), APOGEE MBC (PPC) (P2 Ethernet) (All versions), APOGEE MEC (PPC) (BACnet) (All versions), APOGEE MEC (PPC) (P2 Ethernet) (All versions), APOGEE PXC Compact (BACnet) (All versions < V3.5.4), APOGEE PXC Compact (P2 Ethernet) (All versions < V2.8.19), APOGEE PXC Modular (BACnet) (All versions < V3.5.4), APOGEE PXC Modular (P2 Ethernet) (All versions < V2.8.19), Capital VSTAR (All versions with enabled Ethernet options), Desigo PXC00-E.D (All versions >= V2.3 and < V6.30.016), Desigo PXC00-U (All versions >= V2.3 and < V6.30.016), Desigo PXC001-E.D (All versions >= V2.3 and < V6.30.016), Desigo PXC100-E.D (All versions >= V2.3 and < V6.30.016), Desigo PXC12-E.D (All versions >= V2.3 and < V6.30.016), Desigo PXC128-U (All versions >= V2.3 and < V6.30.016), Desigo PXC200-E.D (All versions >= V2.3 and < V6.30.016), Desigo PXC22-E.D (All versions >= V2.3 and < V6.30.016), Desigo PXC22.1-E.D (All versions >= V2.3 and < V6.30.016), Desigo PXC36.1-E.D (All versions >= V2.3 and < V6.30.016), Desigo PXC50-E.D (All versions >= V2.3 and < V6.30.016), Desigo PXC64-U (All versions >= V2.3 and < V6.30.016), Desigo PXM20-E (All versions >= V2.3 and < V6.30.016), Nucleus NET (All versions), Nucleus ReadyStart V3 (All versions < V2017.02.4), Nucleus Source Code (All versions), TALON TC Compact (BACnet) (All versions < V3.5.4), TALON TC Modular (BACnet) (All versions < V3.5.4). The DHCP client application assumes that the data supplied with the “Hostname” DHCP option is NULL terminated. In cases when global hostname variable is not defined, this may lead to Out-of-bound reads, writes, and Denial-of-service conditions. (FSMD-2021-0014)
Weakness: CWE-170
Which versions are affected by CVE-2021-31884?
It affects 23 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 Desigo Pxc00-E.d Firmware and 17 more.
How do I fix CVE-2021-31884?
No fix has been published for CVE-2021-31884 yet. Limit exposure of the affected software until one is available.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2021-31884 being exploited?
There is no known exploitation of CVE-2021-31884 in the wild and no public exploit code.
Other vulnerabilities in Siemens 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)
- CVE-2021-31346 Denial of service in Capital Embedded AR Classic 431-422
Sources
Also known as GHSA-7p4v-ppf8-95r7.