CVE-2021-40542
Opensis-Classic Version 8.0 is affected by cross-site scripting (XSS). An unauthenticated user...
Opensis-Classic Version 8.0 is affected by cross-site scripting (XSS). An unauthenticated user can inject and execute JavaScript code through the link_url parameter in Ajax_url_encode.php.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Required
What an attacker can affect
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
NVD Score used
Opensis-Classic Version 8.0 is affected by cross-site scripting (XSS). An unauthenticated user can inject and execute JavaScript code through the link_url parameter in Ajax_url_encode.php.
- Record
CVE-2021-40542- CVSS 3.1
- 6.1 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N - CVSS 2.0
- 4.3 Medium
AV:N/AC:M/Au:N/C:N/I:P/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
CVE List No score
Opensis-Classic Version 8.0 is affected by cross-site scripting (XSS). An unauthenticated user can inject and execute JavaScript code through the link_url parameter in Ajax_url_encode.php.
- Record
CVE-2021-40542- Updated
- 2026-11-02
EUVDEUVD-2021-27717 No score
Opensis-Classic Version 8.0 is affected by cross-site scripting (XSS). An unauthenticated user can inject and execute JavaScript code through the link_url parameter in Ajax_url_encode.php.
- Record
EUVD-2021-27717- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-88f6-r22m-fxmf No score
Opensis-Classic Version 8.0 is affected by cross-site scripting (XSS). An unauthenticated user...
Opensis-Classic Version 8.0 is affected by cross-site scripting (XSS). An unauthenticated user can inject and execute JavaScript code through the link_url parameter in Ajax_url_encode.php.
- Record
GHSA-88f6-r22m-fxmf- Weakness
- CWE-79
- Updated
- 2026-11-02
OSV
Opensis-Classic Version 8.0 is affected by cross-site scripting (XSS). An unauthenticated user can inject and execute JavaScript code through the link_url parameter in Ajax_url_encode.php.
- Record
CVE-2021-40542- CVSS 3.1
- 6.1 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N - Updated
- 2026-11-02
Affected products
Public exploits
Links only. Every CVE stores no exploit code.
| Source | Link | Date |
|---|---|---|
| Nuclei | Opensis-Classic 8.0 - Cross-Site Scripting |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, Nuclei, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-40542 is a medium vulnerability (CVSS 6.1) in Os4ed Opensis, published October 11, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 3.16%, the 88th percentile. No source names a fixed version.