A heap-based buffer overflow vulnerability exists in the XML Decompression EnumerationUncompressor::UncompressItem functionality of AT&T Lab
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.
- Published
- Aug 13, 2021
- Updated
- Jun 16, 2026
- EPSS
- 2.5% · 84th percentile
- CWE
- CWE-122
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Report tools
Action score
40
Plan
Add it to your regular patch cycle.
- CVSS
- 39 / 40 · 9.8 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 1 / 30 · 2.5%
CNA vs NVD score
- NVD
- 9.8
- CNA · talos
- 8.1
- 1.7 point gap
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for the hundreds of thousands of vulnerabilities in the database; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpAffected systems
| Vendor | Product | CPE |
|---|---|---|
| att | xmill | cpe:2.3:a:att:xmill |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- att xmill0.7
Versions reported by the vendor
Affected version ranges reported by the assigning authority (talos). Independent of NVD's CPE analysis and usually ahead of it.
n/a AT&T
- AT&T Labs Xmill 0.7affected
Same product
att: all recordsOther highest-scoring records for the same primary product.
- CVE-2022-26507A heap-based buffer overflow exists in XML Decompression DecodeTreeBlock in AT&T Labs Xmill 0.7.40Plan
- CVE-2021-21825A heap-based buffer overflow vulnerability exists in the XML Decompression PlainTextUncompressor::UncompressItem functionality of AT&T Labs’40Plan
- CVE-2021-21830A heap-based buffer overflow vulnerability exists in the XML Decompression LabelDict::Load functionality of AT&T Labs’ Xmill 0.7.40Plan
- CVE-2021-21811A memory corruption vulnerability exists in the XML-parsing CreateLabelOrAttrib functionality of AT&T Labs’ Xmill 0.7.39Monitor
- CVE-2021-21828A heap-based buffer overflow vulnerability exists in the XML Decompression DecodeTreeBlock functionality of AT&T Labs Xmill 0.7.39Monitor
- CVE-2021-21827A heap-based buffer overflow vulnerability exists in the XML Decompression DecodeTreeBlock functionality of AT&T Labs Xmill 0.7.39Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
No fix version is recorded for this entry. Check the references for vendor advisories.
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
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Bug bounty scope
The product’s vendor appears in a public program. Matched by name; verify the scope text in the program.
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- high · data can be read
- Integrity
- high · data or configuration can be modified
- Availability
- high · the service can be disrupted
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- High
Weakness class (CWE)
CWE-122 · Heap-based Buffer OverflowCVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
nvd-primary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
ATT&CK techniques
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Change log
No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.