Check the consumer or maintainer documentation, the architecture/design documentation, or the original requirements to ensure that the documentation includes details for how to update the firmware.
CWE-1329 Base Incomplete
Reliance on Component That is Not Updateable
This vulnerability occurs when a product depends on a component that cannot be updated or patched to fix security flaws or critical bugs.
Definition
What is CWE-1329?
This vulnerability occurs when a product depends on a component that cannot be updated or patched to fix security flaws or critical bugs.
When a vulnerability is discovered in an un-updatable component, product owners are left with no practical way to secure their systems. The only recourse is often a complete replacement, which can be prohibitively expensive or operationally disruptive. This leaves the product permanently exposed to attacks or failures. This is a common and severe issue with hardware like ROM chips, firmware, and embedded systems, which historically lack update mechanisms.
Software is not immune, as it can rely on outdated, unsupported third-party libraries or drivers that are essential for functionality but no longer maintained. In critical sectors like healthcare, legacy devices may operate for decades, creating vast attack surfaces with known vulnerabilities and no modern defenses. This reliance on frozen-in-time components creates long-term, unmanageable risk.
Real-world impact
Real-world CVEs caused by CWE-1329
-
Chain: network-attached storage (NAS) device has a critical OS command injection (CWE-78) vulnerability that is actively exploited to place IoT devices into a botnet, but some products are "end-of-support" and cannot be patched (CWE-1277). [REF-1097]
How attackers exploit it
Step-by-step attacker path
- 1
A refrigerator has an Internet interface for the official purpose of alerting the manufacturer when that refrigerator detects a fault. Because the device is attached to the Internet, the refrigerator is a target for hackers who may wish to use the device other potentially more nefarious purposes.
- 2
A System-on-Chip (SOC) implements a Root-of-Trust (RoT) in ROM to boot secure code. However, at times this ROM code might have security vulnerabilities and need to be patched. Since ROM is immutable, it can be impossible to patch.
- 3
ROM does not have built-in application-programming interfaces (APIs) to patch if the code is vulnerable. Implement mechanisms to patch the vulnerable ROM code.
- 4
The example code is taken from the JTAG module of the buggy OpenPiton SoC of HACK@DAC'21. JTAG is protected with a password checker. Access to JTAG operations will be denied unless the correct password is provided by the user. This user-provided password is first sent to the HMAC module where it is hashed with a secret crypto key. This user password hash (pass_hash) is then compared with the hash of the correct password (exp_hash). If they match, JTAG will then be unlocked.
- 5
However, the SoC's crypto key is hardcoded into the design and cannot be updated [REF-1387]. Therefore, if the key is leaked somehow, there is no way to reprovision the key without having the device replaced.
Vulnerable code example
Vulnerable Other
A refrigerator has an Internet interface for the official purpose of alerting the manufacturer when that refrigerator detects a fault. Because the device is attached to the Internet, the refrigerator is a target for hackers who may wish to use the device other potentially more nefarious purposes.
The refrigerator has no means of patching and is hacked becoming a spewer of email spam. Secure code example
Secure Other
The device automatically patches itself and provides considerable more protection against being hacked. 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-1329
- Requirements Specify requirements that each component should be updateable, including ROM, firmware, etc.
- Architecture and Design Design the product to allow for updating of its components. Include the external infrastructure that might be necessary to support updates, such as distribution servers.
- Architecture and Design / Implementation With hardware, support patches that can be programmed in-field or during manufacturing through hardware fuses. This feature can be used for limited patching of devices after shipping, or for the next batch of silicon devices manufactured, without changing the full device ROM.
- Implementation Implement the necessary functionality to allow each component to be updated.
Detection signals
How to detect CWE-1329
Plexicus auto-detects CWE-1329 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.
Frequently asked questions What is CWE-1329?
How serious is CWE-1329?
What languages or platforms are affected by CWE-1329?
How can I prevent CWE-1329?
How does Plexicus detect and fix CWE-1329?
Where can I learn more about CWE-1329?
Frequently asked questions
What is CWE-1329?
This vulnerability occurs when a product depends on a component that cannot be updated or patched to fix security flaws or critical bugs.
How serious is CWE-1329?
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-1329?
MITRE lists the following affected platforms: Not OS-Specific, Not Architecture-Specific, Not Technology-Specific, ICS/OT.
How can I prevent CWE-1329?
Specify requirements that each component should be updateable, including ROM, firmware, etc. Design the product to allow for updating of its components. Include the external infrastructure that might be necessary to support updates, such as distribution servers.
How does Plexicus detect and fix CWE-1329?
Plexicus's SAST engine matches the data-flow signature for CWE-1329 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-1329?
MITRE publishes the canonical definition at https://cwe.mitre.org/data/definitions/1329.html. You can also reference OWASP and NIST documentation for adjacent guidance.
Related weaknesses
Weaknesses related to CWE-1329
CWE-1357 Parent
Reliance on Insufficiently Trustworthy Component
This weakness occurs when a system integrates a component that cannot be fully trusted to meet security, reliability, and maintenance…
CWE-1104 Sibling
Use of Unmaintained Third Party Components
This weakness occurs when software depends on third-party libraries, frameworks, or modules that are no longer actively updated or…
CWE-1277 Child
Firmware Not Updateable
This vulnerability occurs when a hardware product lacks a mechanism for users to install firmware updates, leaving known security flaws…
CWE-1310 Child
Missing Ability to Patch ROM Code
A system or System-on-Chip (SoC) lacks a mechanism to update its initial boot code stored in Read-Only Memory (ROM), permanently exposing…
Resources
Further reading
- MITRE — official CWE-1329 https://cwe.mitre.org/data/definitions/1329.html
- Report on Improving Cybersecurity in the Health Care Industry https://www.phe.gov/Preparedness/planning/CyberTF/Documents/report2017.pdf
- Zyxel Flaw Powers New Mirai IoT Botnet Strain https://krebsonsecurity.com/2020/03/zxyel-flaw-powers-new-mirai-iot-botnet-strain/
- dmi_jtag.sv line 324 https://github.com/HACK-EVENT/hackatdac21/blob/main/piton/design/chip/tile/ariane/src/riscv-dbg/src/dmi_jtag.sv#L324C9-L324C87
- Fix for dmi_jtag.sv https://github.com/HACK-EVENT/hackatdac21/commit/c94ce5f9487a41c77ede0bbc8daf4da66c39f42a
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