Vulnerability Details : CVE-2021-47068
In the Linux kernel, the following vulnerability has been resolved:
net/nfc: fix use-after-free llcp_sock_bind/connect
Commits 8a4cd82d ("nfc: fix refcount leak in llcp_sock_connect()")
and c33b1cc62 ("nfc: fix refcount leak in llcp_sock_bind()")
fixed a refcount leak bug in bind/connect but introduced a
use-after-free if the same local is assigned to 2 different sockets.
This can be triggered by the following simple program:
int sock1 = socket( AF_NFC, SOCK_STREAM, NFC_SOCKPROTO_LLCP );
int sock2 = socket( AF_NFC, SOCK_STREAM, NFC_SOCKPROTO_LLCP );
memset( &addr, 0, sizeof(struct sockaddr_nfc_llcp) );
addr.sa_family = AF_NFC;
addr.nfc_protocol = NFC_PROTO_NFC_DEP;
bind( sock1, (struct sockaddr*) &addr, sizeof(struct sockaddr_nfc_llcp) )
bind( sock2, (struct sockaddr*) &addr, sizeof(struct sockaddr_nfc_llcp) )
close(sock1);
close(sock2);
Fix this by assigning NULL to llcp_sock->local after calling
nfc_llcp_local_put.
This addresses CVE-2021-23134.
Vulnerability category: Memory Corruption
Products affected by CVE-2021-47068
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Exploit prediction scoring system (EPSS) score for CVE-2021-47068
0.01%
Probability of exploitation activity in the next 30 days
EPSS Score History
~ 1 %
Percentile, the proportion of vulnerabilities that are scored at or less
CVSS scores for CVE-2021-47068
Base Score | Base Severity | CVSS Vector | Exploitability Score | Impact Score | Score Source | First Seen |
---|---|---|---|---|---|---|
7.8
|
HIGH | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
1.8
|
5.9
|
NIST | 2024-12-11 |
CWE ids for CVE-2021-47068
-
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.Assigned by: nvd@nist.gov (Primary)
References for CVE-2021-47068
-
https://git.kernel.org/stable/c/18175fe17ae043a0b81e5d511f8817825784c299
net/nfc: fix use-after-free llcp_sock_bind/connect - kernel/git/stable/linux.git - Linux kernel stable treePatch
-
https://git.kernel.org/stable/c/e32352070bcac22be6ed8ab635debc280bb65b8c
net/nfc: fix use-after-free llcp_sock_bind/connect - kernel/git/stable/linux.git - Linux kernel stable treePatch
-
https://git.kernel.org/stable/c/18ae4a192a4496e48a5490b52812645d2413307c
net/nfc: fix use-after-free llcp_sock_bind/connect - kernel/git/stable/linux.git - Linux kernel stable treePatch
-
https://git.kernel.org/stable/c/ccddad6dd28530e716448e594c9ca7c76ccd0570
net/nfc: fix use-after-free llcp_sock_bind/connect - kernel/git/stable/linux.git - Linux kernel stable treePatch
-
https://git.kernel.org/stable/c/374cdde4dcc9c909a60713abdbbf96d5e3e09f91
net/nfc: fix use-after-free llcp_sock_bind/connect - kernel/git/stable/linux.git - Linux kernel stable treePatch
-
https://git.kernel.org/stable/c/48fba458fe54cc2a980a05c13e6c19b8b2cfb610
net/nfc: fix use-after-free llcp_sock_bind/connect - kernel/git/stable/linux.git - Linux kernel stable treePatch
-
https://git.kernel.org/stable/c/26157c82ba756767b2bd66d28a71b1bc454447f6
net/nfc: fix use-after-free llcp_sock_bind/connect - kernel/git/stable/linux.git - Linux kernel stable treePatch
-
https://git.kernel.org/stable/c/6b7021ed36dabf29e56842e3408781cd3b82ef6e
net/nfc: fix use-after-free llcp_sock_bind/connect - kernel/git/stable/linux.git - Linux kernel stable treePatch
-
https://git.kernel.org/stable/c/c61760e6940dd4039a7f5e84a6afc9cdbf4d82b6
net/nfc: fix use-after-free llcp_sock_bind/connect - kernel/git/stable/linux.git - Linux kernel stable treePatch
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