{"id":"CVE-2009-0654","details":"Tor 0.2.0.28, and probably 0.2.0.34 and earlier, allows remote attackers, with control of an entry router and an exit router, to confirm that a sender and receiver are communicating via vectors involving (1) replaying, (2) modifying, (3) inserting, or (4) deleting a single cell, and then observing cell recognition errors at the exit router.  NOTE: the vendor disputes the significance of this issue, noting that the product's design \"accepted end-to-end correlation as an attack that is too expensive to solve.\"","modified":"2026-04-10T03:40:38.453650Z","published":"2009-02-20T19:30:00Z","references":[{"type":"ARTICLE","url":"http://blog.torproject.org/blog/one-cell-enough"},{"type":"EVIDENCE","url":"http://www.blackhat.com/presentations/bh-dc-09/Fu/BlackHat-DC-09-Fu-Break-Tors-Anonymity.pdf"},{"type":"WEB","url":"http://www.blackhat.com/html/bh-dc-09/bh-dc-09-archives.html#Fu"}],"schema_version":"1.7.5"}