Integer overflow in Tor before 0.1.1.20 allows remote attackers to execute arbitrary code via crafted large inputs, which result in a buffer overflow when elements are added to smartlists.

Tor before 0.1.1.20 supports server descriptors that contain hostnames instead of IP addresses, which allows remote attackers to arbitrarily group users by providing preferential address resolution.

Tor before 0.1.1.20 does not sufficiently obey certain firewall options, which allows remote attackers to bypass intended access restrictions for dirservers, direct connections, or proxy servers.

Tor before 0.1.1.20 uses OpenSSL pseudo-random bytes (RAND_pseudo_bytes) instead of cryptographically strong RAND_bytes, and seeds the entropy value at start-up with 160-bit chunks without reseeding, which makes it easier for attackers to conduct brute force guessing attacks.

Tor before 0.1.1.20 creates "internal circuits" primarily consisting of nodes with "useful exit nodes," which allows remote attackers to conduct unspecified statistical attacks.

The privoxy configuration file in Tor before 0.1.1.20, when run on Apple OS X, logs all data via the "logfile", which allows attackers to obtain potentially sensitive information.

Tor before 0.1.1.20 does not validate that a server descriptor's fingerprint line matches its identity key, which allows remote attackers to spoof the fingerprint line, which might be trusted by users or other applications.

Tor before 0.1.1.20 allows remote attackers to identify hidden services via a malicious Tor server that attempts a large number of accesses of the hidden service, which eventually causes a circuit to be built through the malicious server.