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…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.23%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
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.
- CVSS 3.1
- 7.8 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 0.23% probability · 14th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-416
- Affected
- linux/linux kernel
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
References
- https://git.kernel.org/stable/c/18175fe17ae043a0b81e5d511f8817825784c299Patch
- https://git.kernel.org/stable/c/18ae4a192a4496e48a5490b52812645d2413307cPatch
- https://git.kernel.org/stable/c/26157c82ba756767b2bd66d28a71b1bc454447f6Patch
- https://git.kernel.org/stable/c/374cdde4dcc9c909a60713abdbbf96d5e3e09f91Patch
- https://git.kernel.org/stable/c/48fba458fe54cc2a980a05c13e6c19b8b2cfb610Patch
- https://git.kernel.org/stable/c/6b7021ed36dabf29e56842e3408781cd3b82ef6ePatch
- https://git.kernel.org/stable/c/c61760e6940dd4039a7f5e84a6afc9cdbf4d82b6Patch
- https://git.kernel.org/stable/c/ccddad6dd28530e716448e594c9ca7c76ccd0570Patch
- https://git.kernel.org/stable/c/e32352070bcac22be6ed8ab635debc280bb65b8cPatch
- https://git.kernel.org/stable/c/18175fe17ae043a0b81e5d511f8817825784c299Patch
- https://git.kernel.org/stable/c/18ae4a192a4496e48a5490b52812645d2413307cPatch
- https://git.kernel.org/stable/c/26157c82ba756767b2bd66d28a71b1bc454447f6Patch
- https://git.kernel.org/stable/c/374cdde4dcc9c909a60713abdbbf96d5e3e09f91Patch
- https://git.kernel.org/stable/c/48fba458fe54cc2a980a05c13e6c19b8b2cfb610Patch
- https://git.kernel.org/stable/c/6b7021ed36dabf29e56842e3408781cd3b82ef6ePatch
- https://git.kernel.org/stable/c/c61760e6940dd4039a7f5e84a6afc9cdbf4d82b6Patch
- https://git.kernel.org/stable/c/ccddad6dd28530e716448e594c9ca7c76ccd0570Patch
- https://git.kernel.org/stable/c/e32352070bcac22be6ed8ab635debc280bb65b8cPatch
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.