EPIC Seeks CISA Report on Threat of SS7 Surveillance

Following up on a letter from Sen. Wyden to Pres. Biden, on March 12 EPIC submitted a FOIA request to the Department of Homeland Security (DHS) for the unclassified but unpublished report the Cybersecurity and Infrastructure Security Agency (CISA) commissioned in 2022 on the threat of Signaling System 7 (SS7) surveillance and securing America’s communications networks, which Sen. Wyden’s staff viewed in Fall 2023.

SS7 is a protocol used for telecommunications traffic by most of the world’s public switched telephone network (PSTN) calls. Even where networks have been upgraded, devices may switch to SS7 when making phone calls or while transmitting text messages. By one estimate, nine out of ten texts were able to be intercepted due to the weaknesses in SS7.

EPIC requested expedited release of this report, as there is an urgent need to inform the public about the persistence of SS7 vulnerabilities and what CISA’s recommendations are for resolving these threats.

EPIC has consistently advocated for stronger safeguards in America’s communications networks to ensure the data privacy and data security of those who rely on it, and is among the top FOIA litigators in the country, working to ensure transparency and accountability in the government.