commit 2c0487ecfb410d1361b114e60d8e9ffd2ed092ec Author: Nick Mathewson nickm@torproject.org Date: Sat Nov 11 13:56:35 2017 -0500

Handle NULL input to protover_compute_for_old_tor()

Fixes bug 24245; bugfix on 0.2.9.4-alpha. TROVE-2017-010. --- changes/trove-2017-010 | 6 ++++++ src/or/protover.c | 5 +++++ 2 files changed, 11 insertions(+)

diff --git a/changes/trove-2017-010 b/changes/trove-2017-010 new file mode 100644 index 000000000..d5bf9333d --- /dev/null +++ b/changes/trove-2017-010 @@ -0,0 +1,6 @@ + o Major bugfixes (security): + - Fix a denial-of-service issue where an attacker could crash + a directory authority using a malformed router descriptor. + Fixes bug 24245; bugfix on 0.2.9.4-alpha. Also tracked + as TROVE-2017-010 and CVE-2017-8820. + diff --git a/src/or/protover.c b/src/or/protover.c index 0a4d4fb8f..98957cabd 100644 --- a/src/or/protover.c +++ b/src/or/protover.c @@ -694,6 +694,11 @@ protocol_list_contains(const smartlist_t *protos, const char * protover_compute_for_old_tor(const char *version) { + if (version == NULL) { + /* No known version; guess the oldest series that is still supported. */ + version = "0.2.5.15"; + } + if (tor_version_as_new_as(version, FIRST_TOR_VERSION_TO_ADVERTISE_PROTOCOLS)) { return "";