What is CVE-2021-43808?

CVE-2021-43808 is a medium-severity vulnerability in Laravel Framework, classified under Cross-site Scripting. CVSS score: 5.3/10. Published 2021-12-08.

How severe is CVE-2021-43808?

Medium severity. CVSS v3 base score is 5.3 out of 10.

Is CVE-2021-43808 known to be exploited?

2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

XSS in Laravel Framework

CVE-2021-43808

Laravel is a web application framework. Laravel prior to versions 8.75.0, 7.30.6, and 6.20.42 contain a possible cross-site scripting (XSS) vulnerability in the Blade templating engine. A broken HTML element may be clicked and the user taken to another location in their browser due to XSS. This is due to the user being able to guess the parent placeholder SHA-1 hash by trying common names of sections. If the parent template contains an exploitable HTML structure an XSS vulnerability can be exposed. This vulnerability has been patched in versions 8.75.0, 7.30.6, and 6.20.42 by determining the parent placeholder at runtime and using a random hash that is unique to each request.

Vulnerability class: XSS (Cross-Site Scripting)

EPSS: 0.008 (54.1th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N.

Affected products

Laravel Framework — versions >= 8.0.0, < 8.75.0, >= 7.0.0, < 7.30.6, < 6.20.42

Weakness classification (CWE)

Public proof-of-concept exploits

References

security-advisories@github.com (x_refsource_CONFIRM, Exploit, Third Party Advisory)
security-advisories@github.com (Patch, Third Party Advisory, x_refsource_MISC)
security-advisories@github.com (Patch, Third Party Advisory, x_refsource_MISC)
security-advisories@github.com (Patch, Third Party Advisory, x_refsource_MISC)
security-advisories@github.com (Patch, Third Party Advisory, x_refsource_MISC)
security-advisories@github.com (Third Party Advisory, x_refsource_MISC, Release Notes)
security-advisories@github.com (Third Party Advisory, x_refsource_MISC, Release Notes)
security-advisories@github.com (Third Party Advisory, x_refsource_MISC, Release Notes)

Frequently asked questions

What is CVE-2021-43808?: CVE-2021-43808 is a medium-severity vulnerability in Laravel Framework, classified under Cross-site Scripting. CVSS score: 5.3/10. Published 2021-12-08.
How severe is CVE-2021-43808?: Medium severity. CVSS v3 base score is 5.3 out of 10.
Is CVE-2021-43808 known to be exploited?: 2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.