Cyber Resilience

CVE-2021-34436

Critical

Published: 02 September 2021

Published
02 September 2021
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0350 87.9th percentile
Risk Priority 22 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-34436 is a critical-severity Path Traversal (CWE-22) vulnerability in Eclipse Theia. Its CVSS base score is 9.8 (Critical).

Operationally, ranked in the top 12.1% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

In Eclipse Theia 0.1.1 to 0.2.0, it is possible to exploit the default build to obtain remote code execution (and XXE) via the theia-xml-extension. This extension uses lsp4xml (recently renamed to LemMinX) in order to provide language support for XML.…

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This is installed by default.

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

eclipse
theia
0.1.1 — 0.2.0

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-611

Penetration testing includes XML external entity payloads, detecting XXE vulnerabilities and enabling their mitigation.

addresses: CWE-22

Validates pathnames and filenames to prevent traversal outside intended directories.

addresses: CWE-611

Identifies XML external entity processing via monitoring of unusual file/network access or resource usage.

References