Cyber Resilience

CVE-2021-43808

MediumPublic PoC

Published: 08 December 2021

Published
08 December 2021
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 5.3 CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N
EPSS Score 0.0036 58.5th percentile
Risk Priority 11 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-43808 is a medium-severity Cross-site Scripting (CWE-79) vulnerability in Laravel Framework. Its CVSS base score is 5.3 (Medium).

Operationally, ranked in the top 41.5% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

EU & UK References

Vulnerability details

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…

more

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.

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

laravel
framework
≤ 6.20.42 · 7.0.0 — 7.30.6 · 8.0.0 — 8.75.0

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-327

Contacts with security groups provide timely information on broken or risky cryptographic algorithms, reducing the likelihood of their selection and use.

addresses: CWE-79

Penetration testing submits XSS payloads to web applications, detecting cross-site scripting flaws for subsequent remediation.

addresses: CWE-327

Ongoing education and sharing of recommended practices helps organizations identify and migrate away from broken or risky cryptographic algorithms.

addresses: CWE-327

Cross-organization threat feeds commonly include advances in cryptanalysis and active exploits against weak or broken algorithms, allowing organizations to deprecate them proactively.

addresses: CWE-327

Capital planning and funding allow selection and ongoing support of strong cryptographic algorithms rather than weak or broken ones.

addresses: CWE-327

Risk updates surface newly-broken or risky cryptographic algorithms as threat intelligence and computing advances evolve, enabling timely replacement.

addresses: CWE-327

Scanners flag use of broken or weak cryptographic algorithms via known-vulnerability databases.

addresses: CWE-327

Enforces approved cryptographic algorithms for each use case, blocking use of broken or risky algorithms.

References