CWE-1264 Base Incomplete

Hardware Logic with Insecure De-Synchronization between Control and Data Channels

This vulnerability occurs when a hardware design incorrectly forwards data before its security or permission checks have finished processing. It's a timing flaw where the data channel gets ahead of…

Definition

What is CWE-1264?

This vulnerability occurs when a hardware design incorrectly forwards data before its security or permission checks have finished processing. It's a timing flaw where the data channel gets ahead of the control channel, potentially leaking information.
Modern hardware often uses separate control and data channels to boost performance. A bug in the logic that manages errors and security can allow data to 'race ahead' and be used or observed before the system confirms it's safe to do so. This desynchronization creates a critical window where unauthorized data access can happen. The real-world impact is a loss of data confidentiality, as seen in exploits like Meltdown. In that case, a CPU speculatively loaded privileged data for performance, assuming it could clean up all traces if the access was later deemed illegal. However, secret data remained in the microarchitectural state, proving that assumption false and allowing attackers to retrieve it.
Real-world impact

Real-world CVEs caused by CWE-1264

  • CVE-2017-5754

    Systems with microprocessors utilizing speculative execution and indirect branch prediction may allow unauthorized disclosure of information to an attacker with local user access via a side-channel analysis of the data cache.

How attackers exploit it

Step-by-step attacker path

  1. 1

    Identify a code path that handles untrusted input without validation.

  2. 2

    Craft a payload that exercises the unsafe behavior — injection, traversal, overflow, or logic abuse.

  3. 3

    Deliver the payload through a normal request and observe the application's reaction.

  4. 4

    Iterate until the response leaks data, executes attacker code, or escalates privileges.

Vulnerable code example

Vulnerable Other

There are several standard on-chip bus protocols used in modern SoCs to allow communication between components. There are a wide variety of commercially available hardware IP implementing the interconnect logic for these protocols. A bus connects components which initiate/request communications such as processors and DMA controllers (bus masters) with peripherals which respond to requests. In a typical system, the privilege level or security designation of the bus master along with the intended functionality of each peripheral determine the security policy specifying which specific bus masters can access specific peripherals. This security policy (commonly referred to as a bus firewall) can be enforced using separate IP/logic from the actual interconnect responsible for the data routing.

Vulnerable Other 
The firewall and data routing logic becomes de-synchronized due to a hardware logic bug allowing components that should not be allowed to communicate to share data. For example, consider an SoC with two processors. One is being used as a root of trust and can access a cryptographic key storage peripheral. The other processor (application cpu) may run potentially untrusted code and should not access the key store. If the application cpu can issue a read request to the key store which is not blocked due to de-synchronization of data routing and the bus firewall, disclosure of cryptographic keys is possible.
Secure code example

Secure Other

Secure Other 
All data is correctly buffered inside the interconnect until the firewall has determined that the endpoint is allowed to receive the data.
What changed: the unsafe sink is replaced (or the input is validated/escaped) so the same payload no longer triggers the weakness.
Prevention checklist

How to prevent CWE-1264

  • Architecture and Design Thoroughly verify the data routing logic to ensure that any error handling or security checks effectively block illegal dataflows.
Detection signals

How to detect CWE-1264

SAST High

Run static analysis (SAST) on the codebase looking for the unsafe pattern in the data flow.

DAST Moderate

Run dynamic application security testing against the live endpoint.

Runtime Moderate

Watch runtime logs for unusual exception traces, malformed input, or authorization bypass attempts.

Code review Moderate

Code review: flag any new code that handles input from this surface without using the validated framework helpers.

Plexicus auto-fix

Plexicus auto-detects CWE-1264 and opens a fix PR in under 60 seconds.

Codex Remedium scans every commit, identifies this exact weakness, and ships a reviewer-ready pull request with the patch. No tickets. No hand-offs.

Get a demo Try Plexicus free
Frequently asked questions

Frequently asked questions

What is CWE-1264?

This vulnerability occurs when a hardware design incorrectly forwards data before its security or permission checks have finished processing. It's a timing flaw where the data channel gets ahead of the control channel, potentially leaking information.

How serious is CWE-1264?

MITRE has not published a likelihood-of-exploit rating for this weakness. Treat it as medium-impact until your threat model proves otherwise.

What languages or platforms are affected by CWE-1264?

MITRE lists the following affected platforms: Not OS-Specific, Not Architecture-Specific, Not Technology-Specific.

How can I prevent CWE-1264?

Thoroughly verify the data routing logic to ensure that any error handling or security checks effectively block illegal dataflows.

How does Plexicus detect and fix CWE-1264?

Plexicus's SAST engine matches the data-flow signature for CWE-1264 on every commit. When a match is found, our Codex Remedium agent opens a fix PR with the corrected code, tests, and a one-line summary for the reviewer.

Where can I learn more about CWE-1264?

MITRE publishes the canonical definition at https://cwe.mitre.org/data/definitions/1264.html. You can also reference OWASP and NIST documentation for adjacent guidance.

Related weaknesses

Weaknesses related to CWE-1264

CWE-821 Parent

Incorrect Synchronization

This vulnerability occurs when multiple parts of a program, such as threads or processes, access a shared resource like a variable, file,…

CWE-1088 Sibling

Synchronous Access of Remote Resource without Timeout

This vulnerability occurs when an application makes a synchronous call to a remote service or resource but does not set a timeout, or sets…

CWE-572 Sibling

Call to Thread run() instead of start()

This vulnerability occurs when a program incorrectly calls a thread's `run()` method directly, instead of using the `start()` method. This…

CWE-574 Sibling

EJB Bad Practices: Use of Synchronization Primitives

This vulnerability occurs when an Enterprise JavaBeans (EJB) component improperly uses thread synchronization primitives, violating the…

CWE-1037 Peer

Processor Optimization Removal or Modification of Security-critical Code

This vulnerability occurs when a processor's performance optimization unintentionally strips out or alters security-critical code that a…

Resources

Further reading

Ready when you are

Don't Let Security
Weigh You Down.

Stop choosing between AI velocity and security debt. Plexicus is the only platform that runs Vibe Coding Security and ASPM in parallel — one workflow, every codebase.

Get started free Book a demo