The Introduction Client in Briar through 1.5.3 does not implement out-of-band verification for the public keys of introducees. An introducer can launch man-in-the-middle attacks against later private communication between two introduced parties.
https://ethz.ch/content/dam/ethz/special-interest/infk/inst-infsec/appliedcrypto/education/theses/report_YuanmingSong.pdf
Source: Mitre, NVD
Published: 2023-05-24
Updated: 2023-06-01
Base Score: 7.1
Vector: CVSS2#AV:N/AC:H/Au:N/C:C/I:C/A:N
Severity: High
Base Score: 7.4
Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N