SB2021042177 - Fedora 32 update for kernel, kernel-headers, kernel-tools
Published: April 21, 2021
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 2 vulnerabilities.
1) Race condition (CVE-ID: CVE-2021-23133)
CWE-ID: CWE-362 - Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear
The vulnerability allows a local user to escalate privileges on the system.
The vulnerability exists due to a race condition in Linux kernel SCTP sockets (net/sctp/socket.c). If sctp_destroy_sock is called without
sock_net(sk)->sctp.addr_wq_lock then an element is removed from the
auto_asconf_splist list without any proper locking. This can be
exploited by a local user with network service privileges to escalate to
root or from the context of an unprivileged user directly if a
BPF_CGROUP_INET_SOCK_CREATE is attached which denies creation of some
SCTP socket.
2) Out-of-bounds read (CVE-ID: CVE-2021-29155)
CWE-ID: CWE-125 - Out-of-bounds read
CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:P/U:Clear
The vulnerability allows a local user to gain access to potentially sensitive information.
The vulnerability exists in retrieve_ptr_limit in kernel/bpf/verifier.c in the Linux kernel mechanism. A local, special user privileged (CAP_SYS_ADMIN) BPF program running on affected systems may bypass the protection, and execute speculatively out-of-bounds loads from the kernel memory.
Remediation
Install update from vendor's website.