Linux Distros Unpatched Vulnerability : CVE-2021-47299

medium Nessus Plugin ID 246025

Synopsis

The Linux/Unix host has one or more packages installed with a vulnerability that the vendor indicates will not be patched.

Description

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

- In the Linux kernel, the following vulnerability has been resolved: xdp, net: Fix use-after-free in bpf_xdp_link_release The problem occurs between dev_get_by_index() and dev_xdp_attach_link(). At this point, dev_xdp_uninstall() is called. Then xdp link will not be detached automatically when dev is released. But link->dev already points to dev, when xdp link is released, dev will still be accessed, but dev has been released. dev_get_by_index() | link->dev = dev | | rtnl_lock() | unregister_netdevice_many() | dev_xdp_uninstall() | rtnl_unlock() rtnl_lock(); | dev_xdp_attach_link() | rtnl_unlock(); | | netdev_run_todo() // dev released bpf_xdp_link_release() | /* access dev. | use-after-free */ | [ 45.966867] BUG: KASAN: use-after-free in bpf_xdp_link_release+0x3b8/0x3d0 [ 45.967619] Read of size 8 at addr ffff00000f9980c8 by task a.out/732 [ 45.968297] [ 45.968502] CPU: 1 PID: 732 Comm: a.out Not tainted 5.13.0+ #22 [ 45.969222] Hardware name: linux,dummy-virt (DT) [ 45.969795] Call trace: [ 45.970106] dump_backtrace+0x0/0x4c8 [ 45.970564] show_stack+0x30/0x40 [ 45.970981] dump_stack_lvl+0x120/0x18c [ 45.971470] print_address_description.constprop.0+0x74/0x30c [ 45.972182] kasan_report+0x1e8/0x200 [ 45.972659] __asan_report_load8_noabort+0x2c/0x50 [ 45.973273] bpf_xdp_link_release+0x3b8/0x3d0 [ 45.973834] bpf_link_free+0xd0/0x188 [ 45.974315] bpf_link_put+0x1d0/0x218 [ 45.974790] bpf_link_release+0x3c/0x58 [ 45.975291] __fput+0x20c/0x7e8 [ 45.975706] ____fput+0x24/0x30 [ 45.976117] task_work_run+0x104/0x258 [ 45.976609] do_notify_resume+0x894/0xaf8 [ 45.977121] work_pending+0xc/0x328 [ 45.977575] [ 45.977775] The buggy address belongs to the page: [ 45.978369] page:fffffc00003e6600 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x4f998 [ 45.979522] flags:
0x7fffe0000000000(node=0|zone=0|lastcpupid=0x3ffff) [ 45.980349] raw: 07fffe0000000000 fffffc00003e6708 ffff0000dac3c010 0000000000000000 [ 45.981309] raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000 [ 45.982259] page dumped because: kasan: bad access detected [ 45.982948] [ 45.983153] Memory state around the buggy address: [ 45.983753] ffff00000f997f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 45.984645] ffff00000f998000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [ 45.985533] >ffff00000f998080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [ 45.986419] ^ [ 45.987112] ffff00000f998100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [ 45.988006] ffff00000f998180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [ 45.988895] ================================================================== [ 45.989773] Disabling lock debugging due to kernel taint [ 45.990552] Kernel panic - not syncing: panic_on_warn set ... [ 45.991166] CPU: 1 PID: 732 Comm: a.out Tainted: G B 5.13.0+ #22 [ 45.991929] Hardware name: linux,dummy-virt (DT) [ 45.992448] Call trace: [ 45.992753] dump_backtrace+0x0/0x4c8 [ 45.993208] show_stack+0x30/0x40 [ 45.993627] dump_stack_lvl+0x120/0x18c [ 45.994113] dump_stack+0x1c/0x34 [ 45.994530] panic+0x3a4/0x7d8 [ 45.994930] end_report+0x194/0x198 [ 45.995380] kasan_report+0x134/0x200 [ 45.995850]
__asan_report_load8_noabort+0x2c/0x50 [ 45.996453] bpf_xdp_link_release+0x3b8/0x3d0 [ 45.997007] bpf_link_free+0xd0/0x188 [ 45.997474] bpf_link_put+0x1d0/0x218 [ 45.997942] bpf_link_release+0x3c/0x58 [ 45.998429] __fput+0x20c/0x7e8 [ 45.998833] ____fput+0x24/0x30 [ 45.999247] task_work_run+0x104/0x258 [ 45.999731] do_notify_resume+0x894/0xaf8 [ 46.000236] work_pending ---truncated--- (CVE-2021-47299)

Note that Nessus relies on the presence of the package as reported by the vendor.

Solution

There is no known solution at this time.

See Also

https://ubuntu.com/security/CVE-2021-47299

Plugin Details

Severity: Medium

ID: 246025

File Name: unpatched_CVE_2021_47299.nasl

Version: 1.1

Type: local

Agent: unix

Family: Misc.

Published: 8/8/2025

Updated: 8/8/2025

Supported Sensors: Frictionless Assessment AWS, Frictionless Assessment Azure, Frictionless Assessment Agent, Nessus Agent, Agentless Assessment, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 4.4

CVSS v2

Risk Factor: Medium

Base Score: 4.4

Temporal Score: 3.3

Vector: CVSS2#AV:L/AC:M/Au:N/C:P/I:P/A:P

CVSS Score Source: CVE-2021-47299

CVSS v3

Risk Factor: Medium

Base Score: 5.5

Temporal Score: 4.8

Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

CPE: cpe:/o:canonical:ubuntu_linux:20.04:-:lts, p-cpe:/a:canonical:ubuntu_linux:linux-aws-5.11, p-cpe:/a:canonical:ubuntu_linux:linux-gcp-5.19, p-cpe:/a:canonical:ubuntu_linux:linux-lowlatency-hwe-5.19, p-cpe:/a:canonical:ubuntu_linux:linux-gke-4.15, p-cpe:/a:canonical:ubuntu_linux:linux-aws-5.3, p-cpe:/a:canonical:ubuntu_linux:linux-gke-5.15, p-cpe:/a:canonical:ubuntu_linux:linux-aws-5.8, p-cpe:/a:canonical:ubuntu_linux:linux-gcp-6.2, p-cpe:/a:canonical:ubuntu_linux:linux-oem-6.0, p-cpe:/a:canonical:ubuntu_linux:linux-hwe, p-cpe:/a:canonical:ubuntu_linux:linux-azure-5.8, p-cpe:/a:canonical:ubuntu_linux:linux-azure-6.2, p-cpe:/a:canonical:ubuntu_linux:linux-azure-5.3, p-cpe:/a:canonical:ubuntu_linux:linux-gcp-5.8, p-cpe:/a:canonical:ubuntu_linux:linux-nvidia-6.2, p-cpe:/a:canonical:ubuntu_linux:linux-oracle-5.0, p-cpe:/a:canonical:ubuntu_linux:linux-oem-5.6, p-cpe:/a:canonical:ubuntu_linux:linux-aws-6.2, p-cpe:/a:canonical:ubuntu_linux:linux-raspi2, p-cpe:/a:canonical:ubuntu_linux:linux-gke, p-cpe:/a:canonical:ubuntu_linux:linux-hwe-5.19, cpe:/o:canonical:ubuntu_linux:18.04:-:lts, p-cpe:/a:canonical:ubuntu_linux:linux-gkeop-5.4, p-cpe:/a:canonical:ubuntu_linux:linux-intel-5.13, p-cpe:/a:canonical:ubuntu_linux:linux-oracle-5.13, p-cpe:/a:canonical:ubuntu_linux:linux-gke-5.4, p-cpe:/a:canonical:ubuntu_linux:linux-oem, p-cpe:/a:canonical:ubuntu_linux:linux-oracle-5.8, p-cpe:/a:canonical:ubuntu_linux:linux-oem-5.17, p-cpe:/a:canonical:ubuntu_linux:linux-riscv-5.8, p-cpe:/a:canonical:ubuntu_linux:linux-hwe-6.2, p-cpe:/a:canonical:ubuntu_linux:linux-azure-edge, p-cpe:/a:canonical:ubuntu_linux:linux-hwe-5.11, p-cpe:/a:canonical:ubuntu_linux:linux-aws-5.0, p-cpe:/a:canonical:ubuntu_linux:linux-lowlatency-hwe-6.2, p-cpe:/a:canonical:ubuntu_linux:linux-allwinner-5.19, p-cpe:/a:canonical:ubuntu_linux:linux-hwe-5.8, p-cpe:/a:canonical:ubuntu_linux:linux-starfive-5.19, p-cpe:/a:canonical:ubuntu_linux:linux-aws-5.19, p-cpe:/a:canonical:ubuntu_linux:linux-gcp-5.13, p-cpe:/a:canonical:ubuntu_linux:linux-oem-5.14, p-cpe:/a:canonical:ubuntu_linux:linux-hwe-5.13, p-cpe:/a:canonical:ubuntu_linux:linux-oem-5.13, p-cpe:/a:canonical:ubuntu_linux:linux-gcp, p-cpe:/a:canonical:ubuntu_linux:linux-azure-5.19, p-cpe:/a:canonical:ubuntu_linux:linux-gcp-5.3, p-cpe:/a:canonical:ubuntu_linux:linux-gcp-5.11, p-cpe:/a:canonical:ubuntu_linux:linux-azure-fde, p-cpe:/a:canonical:ubuntu_linux:linux-azure, cpe:/o:canonical:ubuntu_linux:16.04:-:lts, p-cpe:/a:canonical:ubuntu_linux:linux-azure-5.11, p-cpe:/a:canonical:ubuntu_linux:linux-azure-fde-5.19, p-cpe:/a:canonical:ubuntu_linux:linux-oracle-5.11, p-cpe:/a:canonical:ubuntu_linux:linux-riscv-5.11, p-cpe:/a:canonical:ubuntu_linux:linux-riscv-5.19, p-cpe:/a:canonical:ubuntu_linux:linux-oracle-5.3, p-cpe:/a:canonical:ubuntu_linux:linux-hwe-edge, p-cpe:/a:canonical:ubuntu_linux:linux-starfive-6.2, cpe:/o:canonical:ubuntu_linux:22.04:-:lts, p-cpe:/a:canonical:ubuntu_linux:linux-oem-6.1, p-cpe:/a:canonical:ubuntu_linux:linux-azure-5.13, p-cpe:/a:canonical:ubuntu_linux:linux-aws-5.13, p-cpe:/a:canonical:ubuntu_linux:linux-riscv, p-cpe:/a:canonical:ubuntu_linux:linux-azure-fde-6.2, p-cpe:/a:canonical:ubuntu_linux:linux-oem-5.10

Required KB Items: Host/local_checks_enabled, Host/cpu, global_settings/vendor_unpatched, Host/OS/identifier

Exploit Ease: No known exploits are available

Vulnerability Publication Date: 1/28/2022

Reference Information

CVE: CVE-2021-47299