7.8

CVE-2021-47248: udp: fix race between close() and udp_abort()

Modified
AliasesUBUNTU-CVE-2021-47248DEBIAN-CVE-2021-47248
Published 21-05-2024Last modified 05-08-2026

Vulnerability summary

CVE-2021-47248 is a high (CVSS 7.8) vulnerability in linux. EPSS estimates a 0.19% chance of exploitation in the next 30 days, higher than 8.7% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 7.8, local access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
7.8/10
010
High · v3.1 (CVE.org)
EPSS score
0.19%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 5 · Related 5
SUSE-SU-2024:1979-1SUSE-SU-2024:1983-1SUSE-SU-2024:2184-1SUSE-SU-2025:1194-1SUSE-SU-2025:1263-1

Timeline

  1. 21-05-2024
    PublishedVulnerability first disclosed.
  2. 05-08-2026
    Last modifiedVulnerability information updated.

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 <kapandey@codeaurora.org>

CVSS metrics

5 scores · 4 sources · 2 versions

EPSS trend

Probability

0.19%

Chance of exploitation in the next 30 days

Percentile

9%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.19% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.

Ubuntu85 products
  • linux< 4.15.0-156.163 | < 5.4.0-81.91
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-aws< 4.15.0-1111.118 | < 5.4.0-1055.58
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Linux2 products
  • linux≥ 5d77dca82839ef016a93ad7acd7058b14d967752, < e3c36c773aed0fef8b1d3d555b43393ec564400f | ≥ 5d77dca82839ef016a93ad7acd7058b14d967752, < a0882f68f54f7a8b6308261acee9bd4faab5a69e | ≥ 5d77dca82839ef016a93ad7acd7058b14d967752, < 2f73448041bd0682d4b552cfd314ace66107f1ad | ≥ 5d77dca82839ef016a93ad7acd7058b14d967752, < 5a88477c1c85e4baa51e91f2d40f2166235daa56 | ≥ 5d77dca82839ef016a93ad7acd7058b14d967752, < 8729ec8a2238152a4afc212a331a6cd2c61aeeac | ≥ 5d77dca82839ef016a93ad7acd7058b14d967752, < 65310b0aff86980a011c7c7bfa487a333d4ca241 | ≥ 5d77dca82839ef016a93ad7acd7058b14d967752, < a8b897c7bcd47f4147d066e22cc01d1026d7640e | 4.9
  • linux_kernel≥ 4.9, < 4.9.274 | ≥ 4.10, < 4.14.238 | ≥ 4.15, < 4.19.196 | ≥ 4.20, < 5.4.128 | ≥ 5.5, < 5.10.46 | ≥ 5.11, < 5.12.13 | 5.13:rc1 | 5.13:rc2 | 5.13:rc3 | 5.13:rc4 | 5.13:rc5 | 5.13:rc6
Debian1 product
  • linux< 5.10.46-1

3 vendors · 88 products

References

11 links
Show all 11 references