Description
O2 UK before 2025-05-19 allows subscribers to determine the Cell ID of other subscribers by initiating an IMS (IP Multimedia Subsystem) call and then reading the utran-cell-id-3gpp field of a Cellular-Network-Info SIP header, aka an ECI (E-UTRAN Cell Identity) leak. The Cell ID might be usable to identify a cell location via crowdsourced data, and might correspond to a small physical area (e.g., if the called party is in a city centre). Removal of the Cellular-Network-Info header is mentioned in section 4.4.19 of ETSI TS 124 229.
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
O2 UK O2
Default version status: unknown
0 to ≤ 2025-05-17affected
References
- https://mastdatabase.co.uk/blog/2025/05/o2-expose-customer-location-call-4g/ ↗
- https://news.ycombinator.com/item?id=44014046 ↗
- https://www.etsi.org/deliver/etsi_ts/124200_124299/124229/15.10.00_60/ts_124229v151000p.pdf ↗
- https://www.ispreview.co.uk/index.php/2025/05/o2-uk-fixes-volte-flaw-that-exposed-user-mobile-location-data.html ↗