CVE-2021-47593
Global infos:
In the Linux kernel, the following vulnerability has been resolved: mptcp: clear 'kern' flag from fallback sockets The mptcp ULP extension relies on sk->sk_sock_kern being set correctly: It prevents setsockopt(fd, IPPROTO_TCP, TCP_ULP, "mptcp", 6); from working for plain tcp sockets (any userspace-exposed socket). But in case of fallback, accept() can return a plain tcp sk. In such case, sk is still tagged as 'kernel' and setsockopt will work. This will crash the kernel, The subflow extension has a NULL ctx->conn mptcp socket: BUG: KASAN: null-ptr-deref in subflow_data_ready+0x181/0x2b0 Call Trace: tcp_data_ready+0xf8/0x370 [..]
CVE Status: Modified
References:
Metrics:
| Attribute | Value |
|---|---|
| Attack Complexity | LOW |
| Attack Vector | LOCAL |
| Availability Impact | HIGH |
| Base Score | 5.5 |
| Base Severity | MEDIUM |
| Confidentiality Impact | NONE |
| Integrity Impact | NONE |
| Privileges Required | LOW |
| Scope | UNCHANGED |
| User Interaction | NONE |
| Vector String | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
| Exploitability Score | 1.8 |
| Impact Score | 3.6 |
| Source | [email protected] |
| Type | Primary |