7.8

CVE-2021-47259: NFS: Fix use-after-free in nfs4_init_client()

Modified
AliasesUBUNTU-CVE-2021-47259DEBIAN-CVE-2021-47259
Published 21-05-2024Last modified 05-08-2026

Vulnerability summary

CVE-2021-47259 is a high (CVSS 7.8) Use After Free vulnerability in linux. EPSS estimates a 0.71% chance of exploitation in the next 30 days, higher than 53.6% 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
0.71%
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 3 · Related 3
SUSE-SU-2024:2010-1SUSE-SU-2024:2183-1SUSE-SU-2024:2185-1

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: NFS: Fix use-after-free in nfs4_init_client() KASAN reports a use-after-free when attempting to mount two different exports through two different NICs that belong to the same server. Olga was able to hit this with kernels starting somewhere between 5.7 and 5.10, but I traced the patch that introduced the clear_bit() call to 4.13. So something must have changed in the refcounting of the clp pointer to make this call to nfs_put_client() the very last one.

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.71%

Chance of exploitation in the next 30 days

Percentile

54%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.71% 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≥ 8dcbec6d20eb881ba368d0aebc3a8a678aebb1da, < c7eab9e2d7b4e983ce280276fb920af649955897 | ≥ 8dcbec6d20eb881ba368d0aebc3a8a678aebb1da, < 42c10b0db064e45f5c5ae7019bbf2168ffab766c | ≥ 8dcbec6d20eb881ba368d0aebc3a8a678aebb1da, < 3e3c7ebbfac152d08be75c92802a64a1f6471a15 | ≥ 8dcbec6d20eb881ba368d0aebc3a8a678aebb1da, < c3b6cf64dfe4ef96e7341508d50d6998da7062c7 | ≥ 8dcbec6d20eb881ba368d0aebc3a8a678aebb1da, < 72651c6579a25317a90536181d311c663d0329ab | ≥ 8dcbec6d20eb881ba368d0aebc3a8a678aebb1da, < 476bdb04c501fc64bf3b8464ffddefc8dbe01577 | 4.13
  • linux_kernel≥ 4.13, < 4.14.237 | ≥ 4.15, < 4.19.195 | ≥ 4.20, < 5.4.126 | ≥ 5.5, < 5.10.44 | ≥ 5.11, < 5.12.11 | 5.13:rc1 | 5.13:rc2 | 5.13:rc3 | 5.13:rc4 | 5.13:rc5
Debian1 product
  • linux< 5.10.46-1

3 vendors · 88 products

References

10 links