CVE-2021-21303
Vulnerability Scoring
Security assessments indicate that CVE-2021-21303 presents a notable risk, potentially requiring prompt mitigation.
Security assessments indicate that CVE-2021-21303 presents a notable risk, potentially requiring prompt mitigation.
Status: Modified
Last updated: 🕠 21 Nov 2024, 05:47 UTC
Originally published on: 🕙 05 Feb 2021, 22:15 UTC
Time between publication and last update: 1384 days
CVSS Release: version 3
security-advisories@github.com
Secondary
CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:C/C:N/I:H/A:N
CVE-2021-21303: Helm is open-source software which is essentially "The Kubernetes Package Manager". Helm is a tool for managing Charts. Charts are packages of pre-configured Kubernetes resources. In Helm from version 3.0 and before version 3.5.2, there a few cases where data loaded from potentially untrusted sources was not properly sanitized. When a SemVer in the `version` field of a chart is invalid, in some cases Helm allows the string to be used "as is" without sanitizing. Helm fails to properly sanitized some fields present on Helm repository `index.yaml` files. Helm does not properly sanitized some fields in the `plugin.yaml` file for plugins In some cases, Helm does not properly sanitize the fields in the `Chart.yaml` file. By exploiting these attack vectors, core maintainers were able to send deceptive information to a terminal screen running the `helm` command, as well as obscure or alter information on the screen. In some cases, we could send codes that terminals used to execute higher-order logic, like clearing a terminal screen. Further, during evaluation, the Helm maintainers discovered a few other fields that were not properly sanitized when read out of repository index files. This fix remedies all such cases, and once again enforces SemVer2 policies on version fields. All users of the Helm 3 should upgrade to the fixed version 3.5.2 or later. Those who use Helm as a library should verify that they either sanitize this data on their own, or use the proper Helm API calls to sanitize the data.
The exploitability of CVE-2021-21303 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).
CVE-2021-21303 presents an accessible attack vector with minimal effort required. Restricting access controls and implementing security updates are critical to reducing exploitation risks.
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-2021-21303, 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-2021-21303, 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: 0.058% (probability of exploit)
EPSS Percentile: 27.42%
(lower percentile = lower relative risk)
This vulnerability is less risky than approximately 72.58% of others.
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