Ubuntu Linux

A feature in LXD (LP#1829071), affects the default configuration of Ubuntu Server which allows privileged users in the lxd group to escalate their privilege to root without requiring a sudo password.

Published: 2023-12-12T01:51:08.849Z
Updated: 2024-08-02T07:59:44.785Z

Some HTTP/2 implementations are vulnerable to a flood of empty frames, potentially leading to a denial of service. The attacker sends a stream of frames with an empty payload and without the end-of-stream flag. These frames can be DATA, HEADERS, CONTINUATION and/or PUSH_PROMISE. The peer spends time processing each frame disproportionate to attack bandwidth. This can consume excess CPU.

Published: 2019-08-13T20:50:59.000Z
Updated: 2024-08-04T21:54:44.510Z

Some HTTP/2 implementations are vulnerable to unconstrained interal data buffering, potentially leading to a denial of service. The attacker opens the HTTP/2 window so the peer can send without constraint; however, they leave the TCP window closed so the peer cannot actually write (many of) the bytes on the wire. The attacker then sends a stream of requests for a large response object. Depending on how the servers queue the responses, this can consume excess memory, CPU, or both.

Published: 2019-08-13T20:50:59.000Z
Updated: 2024-08-04T21:54:44.675Z

Some HTTP/2 implementations are vulnerable to a header leak, potentially leading to a denial of service. The attacker sends a stream of headers with a 0-length header name and 0-length header value, optionally Huffman encoded into 1-byte or greater headers. Some implementations allocate memory for these headers and keep the allocation alive until the session dies. This can consume excess memory.

Published: 2019-08-13T20:50:59.000Z
Updated: 2024-08-04T21:54:44.285Z

Some HTTP/2 implementations are vulnerable to a settings flood, potentially leading to a denial of service. The attacker sends a stream of SETTINGS frames to the peer. Since the RFC requires that the peer reply with one acknowledgement per SETTINGS frame, an empty SETTINGS frame is almost equivalent in behavior to a ping. Depending on how efficiently this data is queued, this can consume excess CPU, memory, or both.

Published: 2019-08-13T20:50:59.000Z
Updated: 2024-08-04T21:54:44.327Z