CyberSecBulletin
CVE-2022-48651NVD status: Analyzed

Linux: Out-of-bounds Read

Published Updated By the CyberSecBulletin desk

CVE-2022-48651 is a high-severity out-of-bounds read vulnerability in Linux, with a CVSS 3.1 base score of 7.7 out of 10. It can be exploited with local access to the system by an unauthenticated attacker, without any action from a user. The record lists versions e2b46cd5796f083e452fbc624f65b80328b0c1a4, 25efdbe5fe542c3063d1948cc4e98abcb57621ca, bffcdade259c05ab3436b5fab711612093c275ef as the first without the flaw, so updating Linux to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.25% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Linux to e2b46cd5796f083e452fbc624f65b80328b0c1a4 or 25efdbe5fe542c3063d1948cc4e98abcb57621ca or bffcdade259c05ab3436b5fab711612093c275ef or 346e94aa4a99378592c46d6a34c72703a32bd5be, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux2ad7bf3638411cb547f2823df08166c13ab04269 up to, but not including, e2b46cd5796f083e452fbc624f65b80328b0c1a4; 2ad7bf3638411cb547f2823df08166c13ab04269 up to, but not including, 25efdbe5fe542c3063d1948cc4e98abcb57621ca; 2ad7bf3638411cb547f2823df08166c13ab04269 up to, but not including, bffcdade259c05ab3436b5fab711612093c275ef; 2ad7bf3638411cb547f2823df08166c13ab04269 up to, but not including, 346e94aa4a99378592c46d6a34c72703a32bd5be; 2ad7bf3638411cb547f2823df08166c13ab04269 up to, but not including, ab4a733874ead120691e8038272d22f8444d3638; 2ad7bf3638411cb547f2823df08166c13ab04269 up to, but not including, 8d06006c7eb75587d986da46c48ba9274f94e8e7; 2ad7bf3638411cb547f2823df08166c13ab04269 up to, but not including, b583e6b25bf9321c91154f6c78d2173ef12c4241; 2ad7bf3638411cb547f2823df08166c13ab04269 up to, but not including, 81225b2ea161af48e093f58e8dfee6d705b16af4; and 1 more rangese2b46cd5796f083e452fbc624f65b80328b0c1a4, 25efdbe5fe542c3063d1948cc4e98abcb57621ca, bffcdade259c05ab3436b5fab711612093c275ef, 346e94aa4a99378592c46d6a34c72703a32bd5be, ab4a733874ead120691e8038272d22f8444d3638, 8d06006c7eb75587d986da46c48ba9274f94e8e7
Linuxlinux_kernel3.19; 2ad7bf363841Not stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
LocalThe attacker needs local access or must trick a user into running something.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
NoneNo data is disclosed.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H. Scored by CISA (ADP).

Official description

In the Linux kernel, the following vulnerability has been resolved: ipvlan: Fix out-of-bound bugs caused by unset skb->mac_header If an AF_PACKET socket is used to send packets through ipvlan and the default xmit function of the AF_PACKET socket is changed from dev_queue_xmit() to packet_direct_xmit() via setsockopt() with the option name of PACKET_QDISC_BYPASS, the skb->mac_header may not be reset and remains as the initial value of 65535, this may trigger slab-out-of-bounds bugs as following: ================================================================= UG: KASAN: slab-out-of-bounds in ipvlan_xmit_mode_l2+0xdb/0x330 [ipvlan] PU: 2 PID: 1768 Comm: raw_send Kdump: loaded Not tainted 6.0.0-rc4+ #6 ardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-1.fc33 all Trace: print_address_description.constprop.0+0x1d/0x160 print_report.cold+0x4f/0x112 kasan_report+0xa3/0x130 ipvlan_xmit_mode_l2+0xdb/0x330 [ipvlan] ipvlan_start_xmit+0x29/0xa0 [ipvlan] __dev_direct_xmit+0x2e2/0x380 packet_direct_xmit+0x22/0x60 packet_snd+0x7c9/0xc40 sock_sendmsg+0x9a/0xa0 __sys_sendto+0x18a/0x230 __x64_sys_sendto+0x74/0x90 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd The root cause is: 1. packet_snd() only reset skb->mac_header when sock->type is SOCK_RAW and skb->protocol is not specified as in packet_parse_headers() 2. packet_direct_xmit() doesn't reset skb->mac_header as dev_queue_xmit() In this case, skb->mac_header is 65535 when ipvlan_xmit_mode_l2() is called. So when ipvlan_xmit_mode_l2() gets mac header with eth_hdr() which use "skb->head + skb->mac_header", out-of-bound access occurs. This patch replaces eth_hdr() with skb_eth_hdr() in ipvlan_xmit_mode_l2() and reset mac header in multicast to solve this out-of-bound bug.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Out-of-bounds Read

The product reads data past the end, or before the beginning, of the intended buffer.

How developers prevent this class of flaw

  • Use a language that provides appropriate memory abstractions.

More Out-of-bounds Read vulnerabilities (CWE-125)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Out-of-bounds Read vulnerabilities

Spotted an error? Tell us.