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Fencer Vulns
high 8.1

CVE-2021-21825 json

A heap-based buffer overflow vulnerability exists in the XML Decompression PlainTextUncompressor::UncompressItem functionality of AT&T Labs…

published 2021-08-18 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-8996

cvss
8.1
version 3.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
2.3%
EPSS 2.3% chance of exploitation in 30 days, percentile 83%
public exploits
0
none known

Summary

A heap-based buffer overflow vulnerability exists in the XML Decompression PlainTextUncompressor::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.

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

cisa ICSA-22-223-03 updated cvss 8.1

Schneider Electric EcoStruxure, EcoStruxure Process Expert, SCADAPack RemoteConnect for x70

  • Schneider Electric Software, LLC EcoStruxure Control Expert < 15.1 HF001 (including former Unity Pro) Schneider Electric Software, LLC EcoStruxure Process Expert < 2021 (including former HDCS) Schneider Electric Software, LLC SCADAPack RemoteConnect for x70 < R2.7.3
    affected: mitigation “AT&T Labs have stated this software is longer supported and recommends vendors to move away from using it.” se.com

From CISA ICS and IT advisories (CSAF, https://github.com/cisagov/CSAF), a U.S. Government work; changed: reduced to products, statuses and remediations. CISA notification · csaf

Exploit prediction

2.27% chance of exploitation in the next 30 days, higher than 83% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • talosintelligence.com https://talosintelligence.com/vulnerability_reports/TALOS-2021-1290 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.0 8.1 CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 7.5 AV:N/AC:L/Au:N/C:P/I:P/A:P

Affected products

  • n/a AT&T

Classification

Weakness

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.