nihilist/tor
1
0
Fork 0
mirror of https://gitlab.torproject.org/tpo/core/tor.git synced 2024-11-28 06:13:31 +01:00
Code Issues Packages Projects Releases Wiki Activity

Fix a remotely triggerable assertion failure (CVE-2012-2250)

Browse Source 
If we completed the handshake for the v2 link protocol but wound up
negotiating the wong protocol version, we'd become so confused about
what part of the handshake we were in that we'd promptly die with an
assertion.

This is a fix for CVE-2012-2250; it's a bugfix on 0.2.3.6-alpha.
All servers running that version or later should really upgrade.

Bug and fix from "some guy from France."  I tweaked his code slightly
to make it log the IP of the offending node.
This commit is contained in:
Nick Mathewson 2012-10-23 22:58:38 -04:00
parent b99457d429
commit 758428dd32
2 changed files with 15 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
changes/link_negotiation_assert Normal file
View File

@ -0,0 +1,6 @@
o Major bugfixs (security):
- Fix a group of remotely triggerable assertion failures related to
incorrect link protocol negotiation. Found, diagnosed, and fixed
by "some guy from France." Fix for CVE-2012-2250; bugfix on
0.2.3.6-alpha.

9
src/or/command.c
View File

@ -719,6 +719,15 @@ command_process_versions_cell(var_cell_t *cell, or_connection_t *conn)
"handshake. Closing connection.");
connection_mark_for_close(TO_CONN(conn));
return;
} else if (highest_supported_version != 2 &&
conn->_base.state == OR_CONN_STATE_OR_HANDSHAKING_V2) {
/* XXXX This should eventually be a log_protocol_warn */
log_fn(LOG_WARN, LD_OR,
"Negotiated link with non-2 protocol after doing a v2 TLS "
"handshake with %s. Closing connection.",
fmt_addr(&conn->_base.addr));
connection_mark_for_close(TO_CONN(conn));
return;
}
conn->link_proto = highest_supported_version;