CVE-2021-47175

HIGHNVD 7.17.1—
EchelonGraph scoreMEDIUM confidence

Score 7.1 from GitHub Security Advisory (severity: HIGH) published 2024-03-25. NVD baseline CVSS 7.1; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
7.1EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.1Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

In the Linux kernel, the following vulnerability has been resolved:

net/sched: fq_pie: fix OOB access in the traffic path

the following script:

# tc qdisc add dev eth0 handle 0x1 root fq_pie flows 2 # tc qdisc add dev eth0 clsact # tc filter add dev eth0 egress matchall action skbedit priority 0x10002 # ping 192.0.2.2 -I eth0 -c2 -w1 -q

produces the following splat:

BUG: KASAN: slab-out-of-bounds in fq_pie_qdisc_enqueue+0x1314/0x19d0 [sch_fq_pie] Read of size 4 at addr ffff888171306924 by task ping/942

CPU: 3 PID: 942 Comm: ping Not tainted 5.12.0+ #441 Hardware name: Red Hat KVM, BIOS 1.11.1-4.module+el8.1.0+4066+0f1aadab 04/01/2014 Call Trace: dump_stack+0x92/0xc1 print_address_description.constprop.7+0x1a/0x150 kasan_report.cold.13+0x7f/0x111 fq_pie_qdisc_enqueue+0x1314/0x19d0 [sch_fq_pie] __dev_queue_xmit+0x1034/0x2b10 ip_finish_output2+0xc62/0x2120 __ip_finish_output+0x553/0xea0 ip_output+0x1ca/0x4d0 ip_send_skb+0x37/0xa0 raw_sendmsg+0x1c4b/0x2d00 sock_sendmsg+0xdb/0x110 __sys_sendto+0x1d7/0x2b0 __x64_sys_sendto+0xdd/0x1b0 do_syscall_64+0x3c/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7fe69735c3eb Code: 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 f3 0f 1e fa 48 8d 05 75 42 2c 00 41 89 ca 8b 00 85 c0 75 14 b8 2c 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 75 c3 0f 1f 40 00 41 57 4d 89 c7 41 56 41 89 RSP: 002b:00007fff06d7fb38 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 000055e961413700 RCX: 00007fe69735c3eb RDX: 0000000000000040 RSI: 000055e961413700 RDI: 0000000000000003 RBP: 0000000000000040 R08: 000055e961410500 R09: 0000000000000010 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fff06d81260 R13: 00007fff06d7fb40 R14: 00007fff06d7fc30 R15: 000055e96140f0a0

Allocated by task 917: kasan_save_stack+0x19/0x40 __kasan_kmalloc+0x7f/0xa0 __kmalloc_node+0x139/0x280 fq_pie_init+0x555/0x8e8 [sch_fq_pie] qdisc_create+0x407/0x11b0 tc_modify_qdisc+0x3c2/0x17e0 rtnetlink_rcv_msg+0x346/0x8e0 netlink_rcv_skb+0x120/0x380 netlink_unicast+0x439/0x630 netlink_sendmsg+0x719/0xbf0 sock_sendmsg+0xe2/0x110 ____sys_sendmsg+0x5ba/0x890 ___sys_sendmsg+0xe9/0x160 __sys_sendmsg+0xd3/0x170 do_syscall_64+0x3c/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xae

The buggy address belongs to the object at ffff888171306800 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 36 bytes to the right of 256-byte region [ffff888171306800, ffff888171306900) The buggy address belongs to the page: page:00000000bcfb624e refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x171306 head:00000000bcfb624e order:1 compound_mapcount:0 flags: 0x17ffffc0010200(slab|head|node=0|zone=2|lastcpupid=0x1fffff) raw: 0017ffffc0010200 dead000000000100 dead000000000122 ffff888100042b40 raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected

Memory state around the buggy address: ffff888171306800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888171306880: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc >ffff888171306900: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff888171306980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888171306a00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb

fix fq_pie traffic path to avoid selecting 'q->flows + q->flows_cnt' as a valid flow: it's an address beyond the allocated memory.

CVSS v3
7.1
EG Score
7.1(medium)
EG Risk
32(Track)
EG Risk 32/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity71% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
14%
KEV
Not listed

Published

March 25, 2024

Last Modified

August 5, 2026

Advisory Details (3)

Auto-updated Aug 5, 2026
No patch confirmed yet.
generic

net/sched: fq_pie: fix OOB access in the traffic path - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/e70f7a11876a1a788ceadf75e9e5f7af2c868680
generic

net/sched: fq_pie: fix OOB access in the traffic path - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/7a1bdec12e43e29cc34a4394590337069d8812ce
generic

net/sched: fq_pie: fix OOB access in the traffic path - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/e6294c06e7c62ffdd5bf3df696d3a4fcbb753d3c

Affected Packages

(4 across 4 ecosystems)
Debian:11(1)
PackageVulnerable rangeFixed inDependents
linux—5.10.46-1—
Debian:12(1)
PackageVulnerable rangeFixed inDependents
linux—5.14.6-1—
Debian:13(1)
PackageVulnerable rangeFixed inDependents
linux—5.14.6-1—
Debian:14(1)
PackageVulnerable rangeFixed inDependents
linux—5.14.6-1—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 8× in last 7d / 29× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

Showing the most recent 100 of 170 total refreshes for this CVE.

  1. 2026-09-24 14:00 UTCEPSS rescore
  2. 2026-09-24 14:00 UTCEPSS rescore
  3. 2026-09-23 13:45 UTCEPSS rescore
  4. 2026-09-22 14:44 UTCEPSS rescore
  5. 2026-09-21 20:28 UTCEPSS rescore
  6. 2026-09-20 20:13 UTCEPSS rescore
  7. 2026-09-19 15:38 UTCEPSS rescore
  8. 2026-09-18 19:24 UTCEPSS rescore
  9. 2026-09-17 19:23 UTCEPSS rescore
  10. 2026-09-16 14:05 UTCEPSS rescore
  11. 2026-09-16 14:05 UTCEPSS rescore
  12. 2026-09-15 03:06 UTCEPSS rescore
  13. 2026-09-12 14:57 UTCEPSS rescore
  14. 2026-09-11 14:49 UTCEPSS rescore
  15. 2026-09-11 09:33 UTCEPSS rescore
  16. 2026-09-08 21:57 UTCEPSS rescore
  17. 2026-09-07 15:58 UTCEPSS rescore
  18. 2026-09-07 05:18 UTCOSV refresh
  19. 2026-09-06 13:45 UTCEPSS rescore
  20. 2026-09-05 15:25 UTCEPSS rescore
  21. 2026-09-04 13:57 UTCEPSS rescore
  22. 2026-09-04 05:03 UTCEPSS rescore
  23. 2026-09-02 14:09 UTCEPSS rescore
  24. 2026-09-01 13:51 UTCEPSS rescore
  25. 2026-08-30 19:14 UTCEPSS rescore
Show 75 more
  1. 2026-08-30 01:19 UTCEPSS rescore
  2. 2026-08-28 21:38 UTCEPSS rescore
  3. 2026-08-27 14:22 UTCEPSS rescore
  4. 2026-08-26 14:43 UTCEPSS rescore
  5. 2026-08-25 13:46 UTCEPSS rescore
  6. 2026-08-24 14:13 UTCEPSS rescore
  7. 2026-08-21 23:46 UTCEPSS rescore
  8. 2026-08-20 22:52 UTCEPSS rescore
  9. 2026-08-20 15:31 UTCOSV refresh
  10. 2026-08-19 17:01 UTCEPSS rescore
  11. 2026-08-18 13:45 UTCEPSS rescore
  12. 2026-08-17 13:44 UTCEPSS rescore
  13. 2026-08-16 14:53 UTCEPSS rescore
  14. 2026-08-16 02:11 UTCEPSS rescore
  15. 2026-08-15 01:27 UTCEPSS rescore
  16. 2026-08-13 21:57 UTCEPSS rescore
  17. 2026-08-12 13:48 UTCEPSS rescore
  18. 2026-08-11 13:38 UTCEPSS rescore
  19. 2026-08-09 13:44 UTCEPSS rescore
  20. 2026-08-08 16:34 UTCEPSS rescore
  21. 2026-08-07 16:24 UTCEPSS rescore
  22. 2026-08-06 13:44 UTCEPSS rescore
  23. 2026-08-05 19:15 UTCEPSS rescore
  24. 2026-08-05 09:42 UTCEG score recompute
  25. 2026-08-05 09:42 UTCGHSA enrichment
  26. 2026-08-04 15:06 UTCEPSS rescore
  27. 2026-08-04 12:20 UTCEG score recompute
  28. 2026-08-04 12:20 UTCGHSA enrichment
  29. 2026-08-04 10:34 UTCEPSS rescore
  30. 2026-08-04 09:53 UTCEG score recompute
  31. 2026-08-04 09:53 UTCGHSA enrichment
  32. 2026-08-03 10:33 UTCEPSS rescore
  33. 2026-08-02 02:24 UTCEPSS rescore
  34. 2026-08-01 09:06 UTCOSV refresh
  35. 2026-08-01 04:13 UTCEPSS rescore
  36. 2026-07-30 16:25 UTCEPSS rescore
  37. 2026-07-30 01:28 UTCEPSS rescore
  38. 2026-07-28 15:33 UTCEPSS rescore
  39. 2026-07-26 14:52 UTCEPSS rescore
  40. 2026-07-25 14:15 UTCEPSS rescore
  41. 2026-07-24 14:15 UTCEPSS rescore
  42. 2026-07-24 14:15 UTCEPSS rescore
  43. 2026-07-23 14:16 UTCEPSS rescore
  44. 2026-07-23 02:06 UTCEG score recompute
  45. 2026-07-22 22:52 UTCEG score recompute
  46. 2026-07-22 14:06 UTCEPSS rescore
  47. 2026-07-21 15:22 UTCEPSS rescore
  48. 2026-07-21 15:22 UTCEPSS rescore
  49. 2026-07-20 17:05 UTCEPSS rescore
  50. 2026-07-19 14:29 UTCEPSS rescore
  51. 2026-07-19 02:27 UTCEPSS rescore
  52. 2026-07-19 02:27 UTCEPSS rescore
  53. 2026-07-18 10:02 UTCEPSS rescore
  54. 2026-07-16 17:00 UTCEPSS rescore
  55. 2026-07-16 17:00 UTCEPSS rescore
  56. 2026-07-15 16:55 UTCEPSS rescore
  57. 2026-07-15 01:58 UTCEPSS rescore
  58. 2026-07-15 01:58 UTCEPSS rescore
  59. 2026-07-14 16:10 UTCOSV refresh
  60. 2026-07-13 22:27 UTCEPSS rescore
  61. 2026-07-13 06:11 UTCEPSS rescore
  62. 2026-07-13 06:11 UTCEPSS rescore
  63. 2026-07-12 05:44 UTCEPSS rescore
  64. 2026-07-11 08:25 UTCEPSS rescore
  65. 2026-07-09 19:07 UTCEPSS rescore
  66. 2026-07-09 19:07 UTCEPSS rescore
  67. 2026-07-08 15:12 UTCEPSS rescore
  68. 2026-07-08 15:12 UTCEPSS rescore
  69. 2026-07-07 13:43 UTCEPSS rescore
  70. 2026-07-06 16:25 UTCEPSS rescore
  71. 2026-07-06 16:25 UTCEPSS rescore
  72. 2026-07-06 02:21 UTCEPSS rescore
  73. 2026-07-06 02:21 UTCEPSS rescore
  74. 2026-07-05 02:28 UTCEPSS rescore
  75. 2026-07-05 02:28 UTCEPSS rescore

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2021-47175?
CVE-2021-47175 is a high vulnerability published on March 25, 2024. In the Linux kernel, the following vulnerability has been resolved: net/sched: fq_pie: fix OOB access in the traffic path the following script: tc qdisc add dev eth0 handle 0x1 root fq_pie flows 2 tc qdisc add dev eth0 clsact tc filter add dev eth0 egress matchall action skbedit priority 0x10002…
When was CVE-2021-47175 disclosed?
CVE-2021-47175 was first published in the National Vulnerability Database on March 25, 2024, with the most recent update on August 5, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2021-47175 actively exploited?
CVE-2021-47175 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 86.4% of all scored CVEs.
What is the CVSS score of CVE-2021-47175?
CVE-2021-47175 has a CVSS v3 base score of 7.1 (NVD).
How do I remediate CVE-2021-47175?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-47175, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2021-47175

Explore →

Is Your Infrastructure Affected by CVE-2021-47175?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Book a Demo →Browse All CVEs