Tor before 0.4.9.11 is prone to a use-after-free (and potential double free) of a conflux object when a recovery leg revives a conflux set whose last linked leg has already been closed. A malicious exit node could use this to crash a client. This is TROVE-2026-026.

Tor before 0.2.0.34 treats incomplete IPv4 addresses as valid, which has unknown impact and attack vectors related to "Spec conformance," as demonstrated using 192.168.0.

Unspecified vulnerability in Tor before 0.2.0.34 allows directory mirrors to cause a denial of service (exit node crash) via "malformed input."

Unspecified vulnerability in Tor before 0.2.0.34 allows directory mirrors to cause a denial of service via unknown vectors.

Unspecified vulnerability in Tor before 0.2.0.34 allows attackers to cause a denial of service (infinite loop) via "corrupt votes."

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."

Unspecified vulnerability in Tor before 0.2.0.33 has unspecified impact and remote attack vectors that trigger heap corruption.

Tor before 0.2.1.22, and 0.2.2.x before 0.2.2.7-alpha, when functioning as a bridge directory authority, allows remote attackers to obtain sensitive information about bridge identities and bridge descriptors via a dbg-stability.txt directory query.

Tor 0.2.2.x before 0.2.2.7-alpha, when functioning as a directory mirror, does not prevent logging of the client IP address upon detection of erroneous client behavior, which might make it easier for local users to discover the identities of clients in opportunistic circumstances by reading log files.

Tor before 0.2.1.22, and 0.2.2.x before 0.2.2.7-alpha, uses deprecated identity keys for certain directory authorities, which makes it easier for man-in-the-middle attackers to compromise the anonymity of traffic sources and destinations.

Tor allows remote attackers to discover the IP address of a hidden service by accessing this service at a high rate, thereby changing the server's CPU temperature and consequently changing the pattern of time values visible through (1) ICMP timestamps, (2) TCP sequence numbers, and (3) TCP timestamps, a different vulnerability than CVE-2006-0414. NOTE: it could be argued that this is a laws-of-physics vulnerability that is a fundamental design limitation of certain hardware implementations, so perhaps this issue should not be included in CVE.

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.

DISPUTED Tor before 0.1.1.20 kills the circuit when it receives an unrecognized relay command, which causes network circuits to be disbanded. NOTE: while this item is listed under the "Security fixes" section of the developer changelog, the developer clarified on 20060707 that this is only a self-DoS. Therefore this issue should not be included in CVE.

Tor client before 0.1.1.20 prefers entry points based on isfast or isstable flags, which could allow remote attackers to be preferred over nodes that are identified as more trustworthy "entry guard" (isguard) systems by directory authorities.

Tor before 0.2.2.34, when configured as a bridge, sets up circuits through a process different from the process used by a client, which makes it easier for remote attackers to enumerate bridges by observing circuit building.

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 uses improper logic to validate the "OR" destination, which allows remote attackers to perform a man-in-the-middle (MITM) attack via unspecified vectors.

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 uses OpenSSL pseudo-random bytes (RANDpseudobytes) instead of cryptographically strong RANDbytes, 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 supports server descriptors that contain hostnames instead of IP addresses, which allows remote attackers to arbitrarily group users by providing preferential address resolution.

TLS handshakes in Tor before 0.1.1.20 generate public-private keys based on TLS context rather than the connection, which makes it easier for remote attackers to conduct brute force attacks on the encryption keys.

Tor before 0.2.2.34, when configured as a bridge, uses direct DirPort access instead of a Tor TLS connection for a directory fetch, which makes it easier for remote attackers to enumerate bridges by observing DirPort connections.

Tor before 0.2.2.24-alpha continues to use a reachable bridge that was previously configured but is not currently configured, which might allow remote attackers to obtain sensitive information about clients in opportunistic circumstances by monitoring network traffic to the bridge port.

Tor before 0.2.2.25-alpha, when configured as a relay without the Nickname configuration option, uses the local hostname as the Nickname value, which allows remote attackers to obtain potentially sensitive information by reading this value.

Tor 0.1.0.13 and earlier, and experimental versions 0.1.1.4-alpha and earlier, does not reject certain weak keys when using ephemeral Diffie-Hellman (DH) handshakes, which allows malicious Tor servers to obtain the keys that a client uses for other systems in the circuit.

Unknown vulnerability in Tor before 0.1.0.10 allows remote attackers to read arbitrary memory and possibly key information from the exit server's process space.

Unspecified vulnerability in (1) Tor 0.1.0.x before 0.1.0.18 and 0.1.1.x before 0.1.1.23, and (2) ScatterChat before 1.0.2, allows remote attackers operating a Tor entry node to route arbitrary Tor traffic through clients or cause a denial of service (flood) via unspecified vectors.

Unspecified vulnerability in the directory server (dirserver) in Tor before 0.1.1.20 allows remote attackers to cause an unspecified denial of service via unknown vectors.

Tor before 0.1.1.20 allows remote attackers to spoof log entries or possibly execute shell code via strings with non-printable characters.

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.