Cyber Resilience

CVE-2021-43853

HighRCE

Published: 22 December 2021

Published
22 December 2021
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 8.7 CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N
EPSS Score 0.0024 47.2th percentile
Risk Priority 18 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-43853 is a high-severity Cross-site Scripting (CWE-79) vulnerability in Ajax.Net Professional Project Ajax.Net Professional. Its CVSS base score is 8.7 (High).

Operationally, ranked at the 47.2th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

Ajax.NET Professional (AjaxPro) is an AJAX framework available for Microsoft ASP.NET. Affected versions of this package are vulnerable to JavaScript object injection which may result in cross site scripting when leveraged by a malicious user. The affected core relates to…

more

JavaScript object creation when parsing json input. Releases before version 21.12.22.1 are affected. A workaround exists that replaces one of the core JavaScript files embedded in the library. See the GHSA-5q7q-qqw2-hjq7 for workaround details.

CWE(s)

Related Threats

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

Affected Assets

ajax.net professional project
ajax.net professional
≤ 21.12.22.1

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-79 CWE-502

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

addresses: CWE-79 CWE-502

Validates web inputs to reject script-related content that could produce XSS.

addresses: CWE-502

Evaluation of untrusted data handling (deserialization testing) reveals unsafe processing, which the required remediation process addresses.

addresses: CWE-502

Untrusted serialized data can be deserialized and observed inside the chamber, blocking gadget-chain exploitation outside the sandbox.

addresses: CWE-79

Output validation against expected content can reject or sanitize script content in generated web pages, reducing XSS exploitability.

addresses: CWE-502

Identifies and blocks malicious code introduced through deserialization of untrusted data at system boundaries.

addresses: CWE-502

Integrity verification of serialized information can detect tampering before deserialization occurs.

addresses: CWE-502

Provenance of associated data allows detection of untrusted sources before deserialization or processing occurs.

References