Rapid7 Vulnerability & Exploit Database

Amazon Linux AMI 2: CVE-2021-4442: Security patch for kernel (ALASKERNEL-5.4-2022-002)

Free InsightVM Trial No Credit Card Necessary
2024 Attack Intel Report Latest research by Rapid7 Labs
Back to Search

Amazon Linux AMI 2: CVE-2021-4442: Security patch for kernel (ALASKERNEL-5.4-2022-002)

Severity
4
CVSS
(AV:L/AC:M/Au:N/C:P/I:P/A:P)
Published
08/29/2024
Created
09/17/2024
Added
09/16/2024
Modified
09/16/2024

Description

In the Linux kernel, the following vulnerability has been resolved: tcp: add sanity tests to TCP_QUEUE_SEQ Qingyu Li reported a syzkaller bug where the repro changes RCV SEQ _after_ restoring data in the receive queue. mprotect(0x4aa000, 12288, PROT_READ) = 0 mmap(0x1ffff000, 4096, PROT_NONE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x1ffff000 mmap(0x20000000, 16777216, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x20000000 mmap(0x21000000, 4096, PROT_NONE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x21000000 socket(AF_INET6, SOCK_STREAM, IPPROTO_IP) = 3 setsockopt(3, SOL_TCP, TCP_REPAIR, [1], 4) = 0 connect(3, {sa_family=AF_INET6, sin6_port=htons(0), sin6_flowinfo=htonl(0), inet_pton(AF_INET6, "::1", &sin6_addr), sin6_scope_id=0}, 28) = 0 setsockopt(3, SOL_TCP, TCP_REPAIR_QUEUE, [1], 4) = 0 sendmsg(3, {msg_name=NULL, msg_namelen=0, msg_iov=[{iov_base="0x0000000000000003\0\0", iov_len=20}], msg_iovlen=1, msg_controllen=0, msg_flags=0}, 0) = 20 setsockopt(3, SOL_TCP, TCP_REPAIR, [0], 4) = 0 setsockopt(3, SOL_TCP, TCP_QUEUE_SEQ, [128], 4) = 0 recvfrom(3, NULL, 20, 0, NULL, NULL) = -1 ECONNRESET (Connection reset by peer) syslog shows: [ 111.205099] TCP recvmsg seq # bug 2: copied 80, seq 0, rcvnxt 80, fl 0 [ 111.207894] WARNING: CPU: 1 PID: 356 at net/ipv4/tcp.c:2343 tcp_recvmsg_locked+0x90e/0x29a0 This should not be allowed. TCP_QUEUE_SEQ should only be used when queues are empty. This patch fixes this case, and the tx path as well.

Solution(s)

  • amazon-linux-ami-2-upgrade-bpftool
  • amazon-linux-ami-2-upgrade-bpftool-debuginfo
  • amazon-linux-ami-2-upgrade-kernel
  • amazon-linux-ami-2-upgrade-kernel-debuginfo
  • amazon-linux-ami-2-upgrade-kernel-debuginfo-common-aarch64
  • amazon-linux-ami-2-upgrade-kernel-debuginfo-common-x86_64
  • amazon-linux-ami-2-upgrade-kernel-devel
  • amazon-linux-ami-2-upgrade-kernel-headers
  • amazon-linux-ami-2-upgrade-kernel-tools
  • amazon-linux-ami-2-upgrade-kernel-tools-debuginfo
  • amazon-linux-ami-2-upgrade-kernel-tools-devel
  • amazon-linux-ami-2-upgrade-perf
  • amazon-linux-ami-2-upgrade-perf-debuginfo
  • amazon-linux-ami-2-upgrade-python-perf
  • amazon-linux-ami-2-upgrade-python-perf-debuginfo

With Rapid7 live dashboards, I have a clear view of all the assets on my network, which ones can be exploited, and what I need to do in order to reduce the risk in my environment in real-time. No other tool gives us that kind of value and insight.

– Scott Cheney, Manager of Information Security, Sierra View Medical Center

;