CVE-2021-28121
Virtual Robots.txt before 1.10 does not block HTML tags in the robots.txt field.
Virtual Robots.txt before 1.10 does not block HTML tags in the robots.txt field.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
NVD Score used
Virtual Robots.txt before 1.10 does not block HTML tags in the robots.txt field.
- Record
CVE-2021-28121- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - CVSS 2.0
- 7.5 High
AV:N/AC:L/Au:N/C:P/I:P/A:P - Updated
- 2026-11-02
CVE List No score
Virtual Robots.txt before 1.10 does not block HTML tags in the robots.txt field.
- Record
CVE-2021-28121- Updated
- 2026-11-02
EUVDEUVD-2021-14822 No score
Virtual Robots.txt before 1.10 does not block HTML tags in the robots.txt field.
- Record
EUVD-2021-14822- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-ppx8-69h9-fch2 No score
Virtual Robots.txt before 1.10 does not block HTML tags in the robots.txt field.
Virtual Robots.txt before 1.10 does not block HTML tags in the robots.txt field.
- Record
GHSA-ppx8-69h9-fch2- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-28121 is a critical vulnerability (CVSS 9.8) in Virtual Robots.txt Project Robots.txt, published August 12, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.67%, the 76th percentile. No source names a fixed version.