CVE-2020-36997
Buffer Overflow in BacklinkSpeed 2.4 Enables Code Execution
Publication date: 2026-01-29
Last updated on: 2026-01-29
Assigner: VulnCheck
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| ksoft | backlinkspeed | 2.4 |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-121 | A stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function). |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
BacklinkSpeed version 2.4 contains a buffer overflow vulnerability that occurs when importing maliciously crafted files. This vulnerability allows an attacker to overwrite the Structured Exception Handler (SEH) chain, which is a mechanism Windows uses to handle exceptions. By corrupting the SEH addresses, the attacker can execute arbitrary code and potentially take control of the application. The exploit involves crafting a payload file that, when imported, triggers the buffer overflow and SEH overwrite. [2, 3]
How can this vulnerability impact me? :
This vulnerability can allow an attacker to execute arbitrary code within the context of the BacklinkSpeed application, potentially gaining control over it. This could lead to unauthorized actions, data corruption, or further compromise of the system where the application is running. Since the vulnerability requires importing a malicious file, an attacker would need to trick a user into importing such a file, but once exploited, it can severely impact confidentiality, integrity, and availability of the application. [2, 3]
How can this vulnerability be detected on my network or system? Can you suggest some commands?
This vulnerability can be detected by attempting to reproduce the buffer overflow condition using the provided proof-of-concept (PoC) exploit. The PoC involves generating a specially crafted payload file (e.g., 'payload.txt') containing a sequence of characters designed to overwrite the Structured Exception Handler (SEH) chain. To detect the vulnerability, you can run the Python exploit script from Resource 3 to create the payload file, then import this file into BacklinkSpeed 2.4 via its import function. If the application crashes or exhibits abnormal behavior (such as SEH overwrite), the vulnerability is present. There are no specific network commands since the attack is local and requires user interaction. The detection method is primarily manual and involves running the exploit steps: 1) Install and run BacklinkSpeed 2.4. 2) Execute the Python script to generate the payload file. 3) Import the payload file into the application and observe for crashes or SEH corruption. [3]
What immediate steps should I take to mitigate this vulnerability?
Immediate mitigation steps include: 1) Avoid importing files from untrusted or unknown sources into BacklinkSpeed 2.4 to prevent triggering the buffer overflow. 2) Restrict user interaction with the import functionality or disable the import feature if possible until a patch or update is available. 3) Monitor and limit local access to the application to trusted users only. 4) Apply any available software updates or patches from the vendor once released. Since the vulnerability requires local user interaction and crafted files, controlling file imports and user privileges is critical to mitigation. [2, 3]