CVE-2017-20228
Stack-Based Buffer Overflow in Flat Assembler 1.71.21 Enables Code Execution
Publication date: 2026-03-28
Last updated on: 2026-04-02
Assigner: VulnCheck
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| flatassembler | flat_assembler | to 1.71.21 (inc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-787 | The product writes data past the end, or before the beginning, of the intended buffer. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
CVE-2017-20228 is a stack-based buffer overflow vulnerability in Flat Assembler version 1.71.21 and earlier. It occurs when the application processes malicious assembly input that exceeds 5895 bytes, which overwrites the instruction pointer on the stack.
This overflow allows local attackers to execute arbitrary code by crafting input that enables return-oriented programming (ROP) chains, ultimately allowing them to execute shell commands within the context of the application.
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
The vulnerability in Flat Assembler 1.71.21 allows local attackers to execute arbitrary code with high impact on confidentiality, integrity, and availability of the affected system.
Such a compromise could potentially lead to unauthorized access to sensitive data or disruption of services, which may affect compliance with standards and regulations like GDPR or HIPAA that require protection of data confidentiality and system integrity.
However, the provided information does not explicitly discuss or analyze the direct impact of this vulnerability on compliance with these or other common standards and regulations.
How can this vulnerability impact me? :
This vulnerability can have severe impacts including allowing local attackers to execute arbitrary code on the affected system.
- Attackers can gain control over the application by executing shell commands.
- It can lead to a full compromise of confidentiality, integrity, and availability of the system running Flat Assembler.
- Failed exploitation attempts may cause denial-of-service (DoS) conditions by crashing the application.
How can this vulnerability be detected on my network or system? Can you suggest some commands?
This vulnerability can be detected by identifying if Flat Assembler version 1.7.21 or earlier is installed and in use on your system, as these versions are vulnerable to a stack-based buffer overflow triggered by oversized input exceeding 5895 bytes.
Detection involves monitoring for unusually large assembly input files or commands supplied to the Flat Assembler binary that exceed this size threshold, which could indicate an attempted exploit.
Since the vulnerability is local and triggered by input size, you can check the version of Flat Assembler installed using commands like:
- flatasm -v
- flatasm --version
Additionally, you can monitor process execution or command-line arguments for unusually large input files or scripts targeting Flat Assembler.
What immediate steps should I take to mitigate this vulnerability?
Immediate mitigation steps include:
- Avoid using Flat Assembler version 1.7.21 or earlier until a patched version is available.
- Restrict local user access to the Flat Assembler binary to trusted users only, as the attack requires local access.
- Monitor and limit the size of assembly input files or commands supplied to Flat Assembler to prevent oversized inputs exceeding 5895 bytes.
- Consider applying security mitigations such as enabling NX (No-eXecute) and other memory protection features if supported by your environment.
Ultimately, update to a fixed version of Flat Assembler once available to fully remediate the vulnerability.