CVE-2021-42841
Insta HMS before 12.4.10 is vulnerable to XSS because of improper validation of user-supplied...
Insta HMS before 12.4.10 is vulnerable to XSS because of improper validation of user-supplied input by multiple scripts. A remote attacker could exploit this vulnerability via a crafted URL to execute script in a victim's Web browser within the security context of the hosting Web site, once the URL is clicked. An attacker could use this vulnerability to steal the victim's cookie-based authentication credentials.
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
Insta HMS before 12.4.10 is vulnerable to XSS because of improper validation of user-supplied input by multiple scripts. A remote attacker could exploit this vulnerability via a crafted URL to execute script in a victim's Web browser within the security context of the hosting Web site, once the URL is clicked. An attacker could use this vulnerability to steal the victim's cookie-based authentication credentials.
- Record
CVE-2021-42841- 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
Insta HMS before 12.4.10 is vulnerable to XSS because of improper validation of user-supplied input by multiple scripts. A remote attacker could exploit this vulnerability via a crafted URL to execute script in a victim's Web browser within the security context of the hosting Web site, once the URL is clicked. An attacker could use this vulnerability to steal the victim's cookie-based authentication credentials.
- Record
CVE-2021-42841- Updated
- 2026-11-02
EUVDEUVD-2021-29796 No score
Insta HMS before 12.4.10 is vulnerable to XSS because of improper validation of user-supplied input by multiple scripts. A remote attacker could exploit this vulnerability via a crafted URL to execute script in a victim's Web browser within the security context of the hosting Web site, once the URL is clicked. An attacker could use this vulnerability to steal the victim's cookie-based authentication credentials.
- Record
EUVD-2021-29796- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-p7q5-gpw3-mqfx No score
Insta HMS before 12.4.10 is vulnerable to XSS because of improper validation of user-supplied...
Insta HMS before 12.4.10 is vulnerable to XSS because of improper validation of user-supplied input by multiple scripts. A remote attacker could exploit this vulnerability via a crafted URL to execute script in a victim's Web browser within the security context of the hosting Web site, once the URL is clicked. An attacker could use this vulnerability to steal the victim's cookie-based authentication credentials.
- Record
GHSA-p7q5-gpw3-mqfx- Weakness
- CWE-79
- 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-2021-42841 is a medium vulnerability (CVSS 6.1) in Practo Insta Hms, published January 6, 2022. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.88%, the 59th percentile. No source names a fixed version.