As a catastrophic security flaw, CVE-2021-39199 has severe implications, demanding immediate intervention.
Status: Modified
Last updated: 🕕 21 Nov 2024, 06:18 UTC
Originally published on: 🕖 07 Sep 2021, 19:15 UTC
Time between publication and last update: 1170 days
CVSS Release: version 3
security-advisories@github.com
Secondary
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N
CVE-2021-39199: remark-html is an open source nodejs library which compiles Markdown to HTML. In affected versions the documentation of remark-html has mentioned that it was safe by default. In practice the default was never safe and had to be opted into. That is, user input was not sanitized. This means arbitrary HTML can be passed through leading to potential XSS attacks. The problem has been patched in 13.0.2 and 14.0.1: `remark-html` is now safe by default, and the implementation matches the documentation. On older affected versions, pass `sanitize: true` if you cannot update.
The exploitability of CVE-2021-39199 depends on two key factors: attack complexity (the level of effort required to execute an exploit) and privileges required (the access level an attacker needs).
With low attack complexity and no required privileges, CVE-2021-39199 is an easy target for cybercriminals. Organizations should prioritize immediate mitigation measures to prevent unauthorized access and data breaches.
A lower complexity and fewer privilege requirements make exploitation easier. Security teams should evaluate these aspects to determine the urgency of mitigation strategies, such as patch management and access control policies.
Attack Complexity (AC) measures the difficulty in executing an exploit. A high AC means that specific conditions must be met, making an attack more challenging, while a low AC means the vulnerability can be exploited with minimal effort.
Privileges Required (PR) determine the level of system access necessary for an attack. Vulnerabilities requiring no privileges are more accessible to attackers, whereas high privilege requirements limit exploitation to authorized users with elevated access.
Above is the CVSS Sub-score Breakdown for CVE-2021-39199, illustrating how Base, Impact, and Exploitability factors combine to form the overall severity rating. A higher sub-score typically indicates a more severe or easier-to-exploit vulnerability.
Below is the Impact Analysis for CVE-2021-39199, showing how Confidentiality, Integrity, and Availability might be affected if the vulnerability is exploited. Higher values usually signal greater potential damage.
The EPSS score estimates the probability that this vulnerability will be exploited in the near future.
EPSS Score: 0.089% (probability of exploit)
EPSS Percentile: 40.47%
(lower percentile = lower relative risk)
This vulnerability is less risky than approximately 59.53% of others.
Stay updated with real-time CVE vulnerabilities and take action to secure your systems. Enhance your cybersecurity posture with the latest threat intelligence and mitigation techniques. Develop the skills necessary to defend against CVEs and secure critical infrastructures. Join the top cybersecurity professionals safeguarding today's infrastructures.