Highly exploitable, CVE-2021-21250 poses a critical security risk that could lead to severe breaches.
Status: Modified
Last updated: 🕠 21 Nov 2024, 05:47 UTC
Originally published on: 🕘 15 Jan 2021, 21:15 UTC
Time between publication and last update: 1405 days
CVSS Release: version 3
security-advisories@github.com
Secondary
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N
CVE-2021-21250: OneDev is an all-in-one devops platform. In OneDev before version 4.0.3, there is a critical vulnerability which may lead to arbitrary file read. When BuildSpec is provided in XML format, the spec is processed by XmlBuildSpecMigrator.migrate(buildSpecString); which processes the XML document without preventing the expansion of external entities. These entities can be configured to read arbitrary files from the file system and dump their contents in the final XML document to be migrated. If the files are dumped in properties included in the YAML file, it will be possible for an attacker to read them. If not, it is possible for an attacker to exfiltrate the contents of these files Out Of Band. This issue was addressed in 4.0.3 by ignoring ENTITY instructions in xml file.
The exploitability of CVE-2021-21250 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-2021-21250 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-2021-21250, 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-2021-21250, 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: 0.072% (probability of exploit)
EPSS Percentile: 34.45%
(lower percentile = lower relative risk)
This vulnerability is less risky than approximately 65.55% of others.
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