CVE-2021-47593

Severity CVSS v4.0:

Pending analysis

Type:

CWE-476 NULL Pointer Dereference

Publication date:

19/06/2024

Last modified:

01/11/2024

Description

In the Linux kernel, the following vulnerability has been resolved: mptcp: clear &#39;kern&#39; 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 &#39;kernel&#39; 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 [..]

Impact

Vector 3.x

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H CVSS v3.1 Severity and Metrics:

Base Score: 5.50 MEDIUM
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Attack Vector (AV): Local
Attack Complexity (AC): Low
Privileges Required (PR): Low
User Interaction (UI): None
Scope (S): Unchanged
Confidentiality (C): None
Integrity (I): None
Availability (A): High

Base Score 3.x

5.50

Severity 3.x

MEDIUM

Vulnerable products and versions

CPE	From	Up to
cpe:2.3:o:linux:linux_kernel::::::::	5.6 (including)	5.10.88 (excluding)
cpe:2.3:o:linux:linux_kernel::::::::	5.11 (including)	5.15.11 (excluding)
cpe:2.3:o:linux:linux_kernel:5.16:rc1::::::
cpe:2.3:o:linux:linux_kernel:5.16:rc2::::::
cpe:2.3:o:linux:linux_kernel:5.16:rc3::::::
cpe:2.3:o:linux:linux_kernel:5.16:rc4::::::
cpe:2.3:o:linux:linux_kernel:5.16:rc5::::::

To consult the complete list of CPE names with products and versions, see this page

CVE-2021-47593

Description

Impact

Vulnerable products and versions

References to Advisories, Solutions, and Tools