CVE-2021-47356mISDN: fix possible use-after-free in HFC_cleanup()
- 7.7HighCVSS base score
- 0.27%Exploitation in 30 daysEPSS · top 81% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
In the Linux kernel, the following vulnerability has been resolved: mISDN: fix possible use-after-free in HFC_cleanup() This module's remove path calls del_timer(). However, that function does not wait until the timer handler finishes. This means that the timer handler may still be running after the driver's remove function has finished, which would result in a use-after-free. Fix by calling del_timer_sync(), which makes sure the timer handler has finished, and unable to re-schedule itself.
Timeline
ID reserved
By Linux
Published
- 24 months later
· 24 months later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| CISA-ADPADP (enrichment) | 3.1 | High7.7 | CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H |
| NVDNVD · Analyzed | 3.1 | High7.7 | CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H |
- EPSS (exploitation in 30 days)
- 0.27% · top 81% of all CVEs (13 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.7.
Affected products
- affected 87c5fa1bb42624254a2013cbbc3b170d6017f5d6 – < 49331c07ef0f8fdfa42b30ba6a83a657b29d7fbe
- affected 87c5fa1bb42624254a2013cbbc3b170d6017f5d6 – < 54ff3202928952a100c477248e65ac6db01258a7
- affected 87c5fa1bb42624254a2013cbbc3b170d6017f5d6 – < 7867ddc5f3de7f289aee63233afc0df4b62834c5
- affected 87c5fa1bb42624254a2013cbbc3b170d6017f5d6 – < 5f2818185da0fe82a932f0856633038b66faf124
- affected 87c5fa1bb42624254a2013cbbc3b170d6017f5d6 – < 3ecd228c636ee17c14662729737fa07242a93cb0
- affected 87c5fa1bb42624254a2013cbbc3b170d6017f5d6 – < b7ee9ae1e0cf55a037c4a99af2acc5d78cb7802d
- affected 87c5fa1bb42624254a2013cbbc3b170d6017f5d6 – < 61370ff07e0acc657559a8fac02551dfeb9d3020
- affected 87c5fa1bb42624254a2013cbbc3b170d6017f5d6 – < ed7c3739d0a07e2ec3ccbffe7e93cea01c438cda
- affected 87c5fa1bb42624254a2013cbbc3b170d6017f5d6 – < 009fc857c5f6fda81f2f7dd851b2d54193a8e733
- affected 2.6.29
- unaffected < 2.6.29
- unaffected 4.4.276 – ≤ 4.4.*
- unaffected 4.9.276 – ≤ 4.9.*
- unaffected 4.14.240 – ≤ 4.14.*
- unaffected 4.19.198 – ≤ 4.19.*
- unaffected 5.4.133 – ≤ 5.4.*
- unaffected 5.10.51 – ≤ 5.10.*
- unaffected 5.12.18 – ≤ 5.12.*
- unaffected 5.13.3 – ≤ 5.13.*
- unaffected 5.14 – ≤ *
References
References9
- https://git.kernel.org/stable/c/49331c07ef0f8fdfa42b30ba6a83a657b29d7fbe (opens in a new tab)x_transferred
- https://git.kernel.org/stable/c/54ff3202928952a100c477248e65ac6db01258a7 (opens in a new tab)x_transferred
- https://git.kernel.org/stable/c/7867ddc5f3de7f289aee63233afc0df4b62834c5 (opens in a new tab)x_transferred
- https://git.kernel.org/stable/c/5f2818185da0fe82a932f0856633038b66faf124 (opens in a new tab)x_transferred
- https://git.kernel.org/stable/c/3ecd228c636ee17c14662729737fa07242a93cb0 (opens in a new tab)x_transferred
- https://git.kernel.org/stable/c/b7ee9ae1e0cf55a037c4a99af2acc5d78cb7802d (opens in a new tab)x_transferred
- https://git.kernel.org/stable/c/61370ff07e0acc657559a8fac02551dfeb9d3020 (opens in a new tab)x_transferred
- https://git.kernel.org/stable/c/ed7c3739d0a07e2ec3ccbffe7e93cea01c438cda (opens in a new tab)x_transferred
- https://git.kernel.org/stable/c/009fc857c5f6fda81f2f7dd851b2d54193a8e733 (opens in a new tab)x_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2021-34361 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2021-47356)Record last updated .