CVE-2021-47248
CVE-2021-47248 is a medium-severity vulnerability in Linux Linux Kernel with a CVSS 3.x base score of 4.7. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-362.
Key facts
- Severity: Medium (CVSS 3.x base score 4.7)
- EPSS exploit prediction: 0% (8th percentile)
- Actively exploited: Not listed in CISA KEV
- EU (EUVD) id: EUVD-2021-33896
- Weakness: CWE-362
- Affected product: Linux Linux Kernel
- Published:
- Last modified:
Description
In the Linux kernel, the following vulnerability has been resolved: udp: fix race between close() and udp_abort() Kaustubh reported and diagnosed a panic in udp_lib_lookup(). The root cause is udp_abort() racing with close(). Both racing functions acquire the socket lock, but udp{v6}_destroy_sock() release it before performing destructive actions. We can't easily extend the socket lock scope to avoid the race, instead use the SOCK_DEAD flag to prevent udp_abort from doing any action when the critical race happens. Diagnosed-and-tested-by: Kaustubh Pandey <[email protected]>
Frequently asked questions
- What is CVE-2021-47248?
- In the Linux kernel, the following vulnerability has been resolved: udp: fix race between close() and udp_abort() Kaustubh reported and diagnosed a panic in udp_lib_lookup(). The root cause is udp_abort() racing with close(). Both racing functions acquire the socket lock, but udp{v6}_destroy_sock() release it before performing destructive actions. We can't easily extend the socket lock scope to avoid the race, instead use the SOCK_DEAD flag to prevent udp_abort from doing any action when the critical race happens. Diagnosed-and-tested-by: Kaustubh Pandey <[email protected]>
- How severe is CVE-2021-47248?
- CVE-2021-47248 has a CVSS 3.x base score of 4.7, rated medium severity. It is exploitable over local access with high attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
- Is CVE-2021-47248 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (8th percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2021-47248?
- CVE-2021-47248 primarily affects Linux Linux Kernel. In total, 7 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
- How do I fix CVE-2021-47248?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
- Does CVE-2021-47248 have an EU (EUVD) identifier?
- Yes. CVE-2021-47248 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2021-33896.
- When was CVE-2021-47248 published?
- CVE-2021-47248 was published on 2024-05-21 and last updated on 2026-06-17.
References
- https://git.kernel.org/stable/c/2f73448041bd0682d4b552cfd314ace66107f1ad
- https://git.kernel.org/stable/c/5a88477c1c85e4baa51e91f2d40f2166235daa56
- https://git.kernel.org/stable/c/65310b0aff86980a011c7c7bfa487a333d4ca241
- https://git.kernel.org/stable/c/8729ec8a2238152a4afc212a331a6cd2c61aeeac
- https://git.kernel.org/stable/c/a0882f68f54f7a8b6308261acee9bd4faab5a69e
- https://git.kernel.org/stable/c/a8b897c7bcd47f4147d066e22cc01d1026d7640e
- https://git.kernel.org/stable/c/e3c36c773aed0fef8b1d3d555b43393ec564400f
Affected products (7)
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:5.13:rc1:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:5.13:rc2:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:5.13:rc3:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:5.13:rc4:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:5.13:rc5:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:5.13:rc6:*:*:*:*:*:*
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