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Fencer Vulns
high 7.7

CVE-2021-21250 json

Post-Auth External Entity Expansion (XXE)

published 2021-01-15 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-8633

cvss
7.7
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.9%
EPSS 0.9% chance of exploitation in 30 days, percentile 61%
public exploits
0
none known

Summary

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.

Patch / fix

  • onedev_project onedev 4.0.3

Exploit prediction

0.94% chance of exploitation in the next 30 days, higher than 61% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.7 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N
NVD 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
NVD 2.0 4.0 AV:N/AC:L/Au:S/C:P/I:N/A:N

Affected products

  • theonedev onedev

Classification

Weakness
  • CWE-538 Insertion of Sensitive Information into Externally-Accessible File or Directory

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.