A heap-based buffer overflow vulnerability exists in the XML Decompression EnumerationUncompressor::UncompressItem functionality of AT&T Labs’ Xmill 0.7. A specially crafted XMI file can lead to remote code execution. An attacker can provide a malicious file to trigger this vulnerability.
CVE-2021-21829
CRITICALNVD 9.89.8—
EchelonGraph scoreMEDIUM confidence
Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2022-05-24. NVD baseline CVSS 9.8; sources differ by 0.0.
Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
9.8
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
- High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 3%CVSS: 9.8Exploit: NoneExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 9.8
- EG Score
- 9.8(medium)
- EPSS
- 83.1%
- KEV
- Not listed
Published
August 13, 2021
Last Modified
November 21, 2024
Advisory Details (1)
Auto-updated Jul 11, 2026No patch confirmed yet.
generic
TALOS-2021-1292 || Cisco Talos Intelligence Group - Comprehensive Threat Intelligence
https://talosintelligence.com/vulnerability_reports/TALOS-2021-1292Weakness Classification(3)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Related CVEs(same CWE)
Same CWE
10 shownCWE-122 · CWE-787
- CVE-2006-10003EG 9.8CRITICAL
- CVE-2007-0158EG 9.8CRITICAL
- CVE-2007-0899EG 9.8CRITICAL
- CVE-2011-2462EG 9.8 KEVEPSS 100%CRITICAL
- CVE-2010-20115EG 9.3CRITICAL
- CVE-2010-4398NVD 7.8EG 9.0 KEVEPSS 94%HIGH
- CVE-2010-3333NVD 7.8EG 9.0 KEVEPSS 100%HIGH
- CVE-2010-2883NVD 7.3EG 9.0 KEVEPSS 100%HIGH
- CVE-2010-1297NVD 7.8EG 9.0 KEVEPSS 100%HIGH
- CVE-2009-3953NVD 8.8EG 9.0 KEVEPSS 100%HIGH
Frequently asked(5)
What is CVE-2021-21829?
CVE-2021-21829 is a critical vulnerability published on August 13, 2021. A heap-based buffer overflow vulnerability exists in the XML Decompression EnumerationUncompressor::UncompressItem functionality of AT&T Labs’ Xmill 0.7. A specially crafted XMI file can lead to remote code execution. An attacker can provide a malicious file to trigger this vulnerability.
When was CVE-2021-21829 disclosed?
CVE-2021-21829 was first published in the National Vulnerability Database on August 13, 2021, with the most recent update on November 21, 2024. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2021-21829 actively exploited?
CVE-2021-21829 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 83.1% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2021-21829?
CVE-2021-21829 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2021-21829?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-21829, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2021-21829
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