What is CWE-1299: Missing Protection Mechanism for Alternate Hardware Interface?+
CWE-1299: Missing Protection Mechanism for Alternate Hardware Interface is a Common Weakness Enumeration (CWE) entry maintained by MITRE. The lack of protections on alternate paths to access control-protected assets (such as unprotected shadow registers and other external facing unguarded interfaces) allows an attacker to bypass existing protections to the asset that are only performed against the primary path. An asset inside a chip might have access-control protections through one interface. However, if all paths to the asset are not protected, an attacker might compromise the asset through alternate paths. These alternate paths could be through shadow or mirror registers inside the IP core, or could be paths from other external-facing interfaces to the IP core or SoC. Consider an SoC with various interfaces such as UART, SMBUS, PCIe, USB, etc. If access control is implemented for SoC internal registers only over the PCIe interface, then an attacker could still modify the SoC internal registers through alternate paths by coming through interfaces such as UART, SMBUS, USB, etc. Alternatively, attackers might be able to bypass existing protections by exploiting unprotected, shadow registers. Shadow registers and mirror registers typically refer to registers that can be accessed from multiple addresses. Writing to or reading from the aliased/mirrored address has the same effect as writing to the address of the main register. They are typically implemented within an IP core or SoC to temporarily hold certain data. These data will later be updated to the main register, and both registers will be in synch. If the shadow registers are not access-protected, attackers could simply initiate transactions to the shadow registers and compromise system security.
What are the security consequences of Missing Protection Mechanism for Alternate Hardware Interface?+
If exploited, CWE-1299 (Missing Protection Mechanism for Alternate Hardware Interface) it can compromise Confidentiality, Integrity, Availability and Access Control, leading to outcomes such as Modify Memory, Read Memory, DoS: Resource Consumption (Other), Execute Unauthorized Code or Commands, Gain Privileges or Assume Identity and Alter Execution Logic.
How do you prevent or mitigate Missing Protection Mechanism for Alternate Hardware Interface?+
Recommended mitigations for CWE-1299 include: Protect assets from accesses against all potential interfaces and alternate paths. Protect assets from accesses against all potential interfaces and alternate paths. Protect assets from accesses against all potential interfaces and alternate paths.
Which programming languages are affected by Missing Protection Mechanism for Alternate Hardware Interface?+
CWE-1299 commonly affects Not Language-Specific. Note that weaknesses are often language-agnostic patterns, so secure coding practices apply broadly.
What are real-world examples of Missing Protection Mechanism for Alternate Hardware Interface?+
MITRE documents real CVEs mapped to CWE-1299, including CVE-2022-38399, CVE-2020-9285, CVE-2020-8004, CVE-2017-18293 and CVE-2020-15483. You can look up the full details of each CVE, including CVSS scores and remediation guidance, on our CVE Lookup tool.
What is the difference between a CWE and a CVE?+
A CWE (Common Weakness Enumeration) like CWE-1299 describes a category of software weakness — the underlying flaw type. A CVE (Common Vulnerabilities and Exposures) identifies a specific, real-world vulnerability in a particular product. In short, a CWE is the kind of mistake, and a CVE is an instance of that mistake being found in software.