What is the CVSS score of CVE-2021-20873?

CVE-2021-20873 has a CVSS 3.1 base score of 8.1 (High). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N. EPSS exploitation probability: 0.8%.

Yappli CVE-2021-20873

HIGH

Missing Authorization (CWE-862)

2021-12-28 vultures@jpcert.or.jp

Google Authentication Bypass Yappli

8.1

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

8.1 HIGH

AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

None

Lifecycle Timeline

CVE Published

Dec 28, 2021 - 02:15 nvd

HIGH 8.1

DescriptionNVD

Yappli is an application development platform which provides the function to access a requested URL using Custom URL Scheme. When Android apps are developed with Yappli versions since v7.3.6 and prior to v9.30.0, they are vulnerable to improper authorization in Custom URL Scheme handler, and may be directed to unintended sites via a specially crafted URL.

AnalysisAI

Yappli is an application development platform which provides the function to access a requested URL using Custom URL Scheme. Rated high severity (CVSS 8.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.

Technical ContextAI

This vulnerability is classified as Missing Authorization (CWE-862), which allows attackers to access resources or perform actions without proper authorization checks. Yappli is an application development platform which provides the function to access a requested URL using Custom URL Scheme. When Android apps are developed with Yappli versions since v7.3.6 and prior to v9.30.0, they are vulnerable to improper authorization in Custom URL Scheme handler, and may be directed to unintended sites via a specially crafted URL. Affected products include: Yappli.

RemediationAI

No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Implement role-based access control, validate authorization on every request server-side, apply principle of least privilege.