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In the Linux kernel, the following vulnerability has been...

High severity Unreviewed Published Mar 1, 2024 to the GitHub Advisory Database • Updated Dec 10, 2024

Package

No package listed— Suggest a package

Affected versions

Unknown

Patched versions

Unknown

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.

References

Published by the National Vulnerability Database Feb 29, 2024
Published to the GitHub Advisory Database Mar 1, 2024
Last updated Dec 10, 2024

Severity

High

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS score

0.042%
(5th percentile)

Weaknesses

CVE ID

CVE-2021-47068

GHSA ID

GHSA-47q3-98v3-643r

Source code

No known source code

Dependabot alerts are not supported on this advisory because it does not have a package from a supported ecosystem with an affected and fixed version.

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