CWE Database
/

CWE-1281

Back to CWE list

CWE-1281

Sequence of Processor Instructions Leads to Unexpected Behavior

Base
Incomplete

Description

Specific combinations of processor instructions lead to undesirable behavior such as locking the processor until a hard reset performed.

{"xhtml:p":["If the instruction set architecture (ISA) and processor logic are not designed carefully and tested thoroughly, certain combinations of instructions may lead to locking the processor or other unexpected and undesirable behavior. Upon encountering unimplemented instruction opcodes or illegal instruction operands, the processor should throw an exception and carry on without negatively impacting security. However, specific combinations of legal and illegal instructions may cause unexpected behavior with security implications such as allowing unprivileged programs to completely lock the CPU. \n "]}

Common Consequences

Scope

Integrity
Availability

Impact

Varies by Context

Potential Mitigations

Testing

Implement a rigorous testing strategy that incorporates randomization to explore instruction sequences that are unlikely to appear in normal workloads in order to identify halt and catch fire instruction sequences.

Patching and Maintenance

Patch operating system to avoid running Halt and Catch Fire type sequences or to mitigate the damage caused by unexpected behavior. See [REF-1108].

CVE-2021-26339

A bug in AMD CPU's core logic allows a potential DoS by using a specific x86 instruction sequence to hang the processor

CVE-1999-1476

A bug in some Intel Pentium processors allow DoS (hang) via an invalid "CMPXCHG8B" instruction, causing a deadlock

Applicable Platforms

Not Language-Specific

Security Training

Train your team to recognize and prevent security threats with our comprehensive security awareness program.

Start Training

Vulnerability Scanning

Discover vulnerabilities in your applications and infrastructure before attackers do.

Scan Now