CVE-2021-33626 Memory corruption in n/a
Attackers can corrupt SMRAM memory and execute arbitrary code via insufficient validation of SWSMI handler buffer pointers in System Management Mode firmware.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2021-33626?
CVE-2021-33626 is a high-severity memory corruption vulnerability in Insyde Insydeh2o, published on 1 Oct 2021. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
A vulnerability exists in SMM (System Management Mode) branch that registers a SWSMI handler that does not sufficiently check or validate the allocated buffer pointer(QWORD values for CommBuffer). This can be used by an attacker to corrupt data in SMRAM memory and even lead to arbitrary code execution.
Weakness: CWE-829
Which versions are affected by CVE-2021-33626?
It affects 17 products.
Products include Insyde Insydeh2o, Siemens Ruggedcom Apr1808 Firmware, Siemens Simatic Field Pg M5 Firmware, Siemens Simatic Field Pg M6 Firmware, Siemens Simatic Ipc127e Firmware, Siemens Simatic Ipc227g Firmware and 11 more.
How do I fix CVE-2021-33626?
No fix has been published for CVE-2021-33626 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-2021-33626 being exploited?
There is no known exploitation of CVE-2021-33626 in the wild and no public exploit code.
Other vulnerabilities in Insyde Insydeh2o
Sources
Also known as GHSA-9g63-gv45-4242.