CVE-2021-47459
HighIn the Linux kernel, the following vulnerability has been resolved: can: j1939: j1939_netdev_start(): fix UAF for rx_kref of j1939_priv It will trigger UAF for rx_kref of j1939_priv as following. cpu0 cpu1 j1939_sk_bind(socket0, ndev0, ...) j1939_netdev_start j1939_sk_bind(socket1, ndev0, ...) j1939_netdev_start j1939_priv_set j1939_priv_get_by_ndev_locked j1939_jsk_add ..... j1939_netdev_stop kref_put_lock(&priv->rx_kref, ...) kref_get(&priv->rx_kref, ...) REFCOUNT_WARN("addition on 0;...") ==================================================== refcount_t: addition on 0; use-after-free. WARNING: CPU: 1 PID: 20874 at lib/refcount.c:25 refcount_warn_saturate+0x169/0x1e0 RIP: 0010:refcount_warn_saturate+0x169/0x1e0 Call Trace: j1939_netdev_start+0x68b/0x920 j1939_sk_bind+0x426/0xeb0 ? security_socket_bind+0x83/0xb0 The rx_kref's kref_get() and kref_put() should use j1939_netdev_lock to protect.
CVSS 3.1 score
7.8
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Weakness type
CWE-416CVE-2021-47459 is a Use After Free vulnerability
What is Use After Free?
The product references memory after it has been freed, which may cause it to crash, use unexpected values, or execute code. Learn more on MITRE CWE
References
The following references provide additional information about CVE-2021-47459 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.
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PatchKernel patch commithttps://git.kernel.org/stable/c/6e8811707e2df0c6ba920f0cad3a3bca7b42132f
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PatchKernel patch commithttps://git.kernel.org/stable/c/864e77771a24c877aaf53aee019f78619cbcd668
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PatchKernel patch commithttps://git.kernel.org/stable/c/a0e47d2833b4f65e6c799f28c6b636d36b8b936d
Frequently asked questions
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What is CVE-2021-47459?
CVE-2021-47459 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10 , classified as an Use After Free flaw (CWE-416) . CVE-2021-47459 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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What is the CVSS score for CVE-2021-47459?
CVE-2021-47459 has a CVSS score of 7.8 out of 10, rated High severity (CVSS 3.1). The vector string is
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. -
Is there a patch available for CVE-2021-47459?
No patch is currently available for CVE-2021-47459. Monitor the NIST NVD and your Linux distribution's security advisories for updates.
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Is CVE-2021-47459 actively exploited?
No — CVE-2021-47459 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.
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What is Use After Free (CWE-416)?
The product references memory after it has been freed, which may cause it to crash, use unexpected values, or execute code. View CWE-416 on MITRE CWE →