NoScript Classic before 5.1.8.7, as used in Tor Browser 7.x and other products, allows attackers to bypass script blocking via the text/html;/json Content-Type value.

Tor before 0.4.9.7 has an out-of-bounds read when an END, a TRUNCATE, or a TRUNCATED cell lacks a reason in its payload, aka TROVE-2026-011.

Tor before 0.4.9.7 has an out-of-bounds read by one byte via a malformed BEGIN cell, aka TROVE-2026-007.

Tor before 0.3.5.10, 0.4.x before 0.4.1.9, and 0.4.2.x before 0.4.2.7 allows remote attackers to cause a Denial of Service (CPU consumption), aka TROVE-2020-002.

Tor before 0.4.9.7 has a NULL pointer dereference when a CERT cell is received out of order, aka TROVE-2026-006.

Tor before 0.4.9.7, when circuit queue memory pressure exists, can experience a client crash because of a double close of a circuit, aka TROVE-2026-009.

A use-after-free vulnerability in SVG Animation has been discovered. An exploit built on this vulnerability has been discovered in the wild targeting Firefox and Tor Browser users on Windows.

An issue was discovered in Tor before 0.4.6.5, aka TROVE-2021-006. The v3 onion service descriptor parsing allows out-of-bounds memory access, and a client crash, via a crafted onion service descriptor

An issue was discovered in Tor before 0.4.6.5, aka TROVE-2021-005. Hashing is mishandled for certain retrieval of circuit data. Consequently. an attacker can trigger the use of an attacker-chosen circuit ID to cause algorithm inefficiency.

The Hidden Service (HS) client implementation in Tor before 0.2.4.27, 0.2.5.x before 0.2.5.12, and 0.2.6.x before 0.2.6.7 allows remote servers to cause a denial of service (assertion failure and application exit) via a malformed HS descriptor.

The Hidden Service (HS) server implementation in Tor before 0.2.4.27, 0.2.5.x before 0.2.5.12, and 0.2.6.x before 0.2.6.7 allows remote attackers to cause a denial of service (assertion failure and daemon exit) via unspecified vectors.

bufpullup in Tor before 0.2.4.26 and 0.2.5.x before 0.2.5.11 does not properly handle unexpected arrival times of buffers with invalid layouts, which allows remote attackers to cause a denial of service (assertion failure and daemon exit) via crafted packets.

Tor before 0.2.4.26 and 0.2.5.x before 0.2.5.11 does not properly handle pending-connection resolve states during periods of high DNS load, which allows remote attackers to cause a denial of service (assertion failure and daemon exit) via crafted packets.

Tor before 0.2.8.12 might allow remote attackers to cause a denial of service (client crash) via a crafted hidden service descriptor.

Tor 0.3.x before 0.3.0.9 has a guard-selection algorithm that only considers the exit relay (not the exit relay's family), which might allow remote attackers to defeat intended anonymity properties by leveraging the existence of large families.

The hidden-service feature in Tor before 0.3.0.8 allows a denial of service (assertion failure and daemon exit) in the connectionedgeprocessrelaycell function via a BEGINDIR cell on a rendezvous circuit.

The hidden-service feature in Tor before 0.3.0.8 allows a denial of service (assertion failure and daemon exit) in the relaysendendcellfromedge function via a malformed BEGIN cell.

Tor before 0.2.8.9 and 0.2.9.x before 0.2.9.4-alpha had internal functions that were entitled to expect that buft data had NUL termination, but the implementation of or/buffers.c did not ensure that NUL termination was present, which allows remote attackers to cause a denial of service (client, hidden service, relay, or authority crash) via crafted data.

Tor before 0.3.5.16, 0.4.5.10, and 0.4.6.7 mishandles the relationship between batch-signature verification and single-signature verification, leading to a remote assertion failure, aka TROVE-2021-007.

Tor before 0.4.5.7 allows a remote participant in the Tor directory protocol to exhaust CPU resources on a target, aka TROVE-2021-001.

Tor before 0.4.3.6 has an out-of-bounds memory access that allows a remote denial-of-service (crash) attack against Tor instances built to use Mozilla Network Security Services (NSS), aka TROVE-2020-001.

Tor before 0.3.5.10, 0.4.x before 0.4.1.9, and 0.4.2.x before 0.4.2.7 allows remote attackers to cause a Denial of Service (memory leak), aka TROVE-2020-004. This occurs in circpadsetupmachineoncirc because a circuit-padding machine can be negotiated twice on the same circuit.

In Tor before 0.3.3.12, 0.3.4.x before 0.3.4.11, 0.3.5.x before 0.3.5.8, and 0.4.x before 0.4.0.2-alpha, remote denial of service against Tor clients and relays can occur via memory exhaustion in the KIST cell scheduler.

An issue was discovered in Tor before 0.2.9.15, 0.3.1.x before 0.3.1.10, and 0.3.2.x before 0.3.2.10. The directory-authority protocol-list subprotocol implementation allows remote attackers to cause a denial of service (NULL pointer dereference and directory-authority crash) via a misformatted relay descriptor that is mishandled during voting.

A use-after-free issue was discovered in Tor 0.3.2.x before 0.3.2.10. It allows remote attackers to cause a denial of service (relay crash) because the KIST implementation allows a channel to be added more than once in the pending list.

A Denial of Service issue was fixed in tor 0.4.7.8 related to congestion control. RTT estimation can become wedged, seriously degrading congestion control performance on all circuits. This impacts clients, onion services, and relays, and can be triggered remotely by a malicious endpoint.

References: https://gitlab.torproject.org/tpo/core/tor/-/issues/40626 https://lists.torproject.org/pipermail/tor-announce/2022-June/000242.html https://github.com/torproject/tor/commit/5a25374209689466e10906a77e66ad717a615a02 https://github.com/torproject/tor/commit/b0496d40197dd5b4fb7b694c1410082d4e34dda6

An issue was discovered in Tor before 0.4.6.5, aka TROVE-2021-003. An attacker can forge RELAYEND or RELAYRESOLVED to bypass the intended access control for ending a stream.

The SafeSocks option in Tor before 0.4.7.13 has a logic error in which the unsafe SOCKS4 protocol can be used but not the safe SOCKS4a protocol, aka TROVE-2022-002.

Browser proxy settings can be bypassed by using the automount feature with autofs to create a mount point on the local file system. Content can be loaded from this mounted file system directly using a file: URI, bypassing configured proxy settings. Note: this issue only affects OS X in default configurations. On Linux systems, autofs must be installed for the vulnerability to occur and Windows is not affected.

Tor Browser through 10.5.6 and 11.x through 11.0a4 allows a correlation attack that can compromise the privacy of visits to v2 onion addresses. Exact timestamps of these onion-service visits are logged locally, and an attacker might be able to compare them to timestamp data collected by the destination server (or collected by a rogue site within the Tor network).