Buffer overflow in AT&T
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-120 and the CVSS impact.
Summary
A heap-based buffer overflow vulnerability exists in the XML Decompression DecodeTreeBlock functionality of AT&T Labs Xmill 0.7. Within `DecodeTreeBlock` which is called during the decompression of an XMI file, a UINT32 is loaded from the file and used as trusted input as the length of a buffer. An attacker can provide a malicious file to trigger this vulnerability.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | AT&T | AT&T Labs Xmill 0.7, Schneider Electric EcoStruxure Control Expert 15 | — | No fix listed | CNA |
- AT&T Vendor— Affected AT&T Labs Xmill 0.7, Schneider Electric EcoStruxure Control Expert 15 Fixed in — No fix listed CNA
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2021-21827
- 2026-10-03 Alias added: GHSA-q52q-979x-2v5q
References
More AT&T Xmill vulnerabilities
- TI-2022-09848 A heap-based buffer overflow exists in XML Decompression DecodeTreeBlock in AT&T Labs… CVSS 3.1CRITICAL 9.8
- TI-2021-04874 Heap-based buffer overflow in AT&T CVSS 3.1CRITICAL 9.8
- TI-2021-04875 Heap-based buffer overflow in AT&T CVSS 3.1CRITICAL 9.8
- TI-2021-04870 Heap-based buffer overflow in AT&T CVSS 3.1CRITICAL 9.8
- TI-2021-04873 Buffer overflow in AT&T CVSS 3.1CRITICAL 9.8
- TI-2021-04871 Buffer overflow in AT&T CVSS 3.1CRITICAL 9.8
Sources
- CVE-2021-21827 · CVE Program
- CVE-2021-21827 · NVD
- FIRST EPSS
- GHSA-q52q-979x-2v5q · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences