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.
CVSS Details
- CVSS 3.1 Base Score: 3.5
- CVSS 3.1 Vector: (CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:N/A:N)
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