7.8

CVE-2021-47588: sit: do not call ipip6_dev_free() from sit_init_net()

Modified
AliasesUBUNTU-CVE-2021-47588DEBIAN-CVE-2021-47588
Published 19-06-2024Last modified 05-08-2026

Vulnerability summary

CVE-2021-47588 is a high (CVSS 7.8) vulnerability in linux. EPSS estimates a 0.26% chance of exploitation in the next 30 days, higher than 18.1% 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
0.26%
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 6 · Related 6
SUSE-SU-2024:2892-1SUSE-SU-2024:2894-1SUSE-SU-2024:2901-1SUSE-SU-2024:2939-1SUSE-SU-2024:2940-1SUSE-SU-2024:2947-1

Timeline

  1. 19-06-2024
    PublishedVulnerability first disclosed.
  2. 05-08-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: sit: do not call ipip6_dev_free() from sit_init_net() ipip6_dev_free is sit dev->priv_destructor, already called by register_netdevice() if something goes wrong. Alternative would be to make ipip6_dev_free() robust against multiple invocations, but other drivers do not implement this strategy. syzbot reported: dst_release underflow WARNING: CPU: 0 PID: 5059 at net/core/dst.c:173 dst_release+0xd8/0xe0 net/core/dst.c:173 Modules linked in: CPU: 1 PID: 5059 Comm: syz-executor.4 Not tainted 5.16.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:dst_release+0xd8/0xe0 net/core/dst.c:173 Code: 4c 89 f2 89 d9 31 c0 5b 41 5e 5d e9 da d5 44 f9 e8 1d 90 5f f9 c6 05 87 48 c6 05 01 48 c7 c7 80 44 99 8b 31 c0 e8 e8 67 29 f9 <0f> 0b eb 85 0f 1f 40 00 53 48 89 fb e8 f7 8f 5f f9 48 83 c3 a8 48 RSP: 0018:ffffc9000aa5faa0 EFLAGS: 00010246 RAX: d6894a925dd15a00 RBX: 00000000ffffffff RCX: 0000000000040000 RDX: ffffc90005e19000 RSI: 000000000003ffff RDI: 0000000000040000 RBP: 0000000000000000 R08: ffffffff816a1f42 R09: ffffed1017344f2c R10: ffffed1017344f2c R11: 0000000000000000 R12: 0000607f462b1358 R13: 1ffffffff1bfd305 R14: ffffe8ffffcb1358 R15: dffffc0000000000 FS: 00007f66c71a2700(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f88aaed5058 CR3: 0000000023e0f000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> dst_cache_destroy+0x107/0x1e0 net/core/dst_cache.c:160 ipip6_dev_free net/ipv6/sit.c:1414 [inline] sit_init_net+0x229/0x550 net/ipv6/sit.c:1936 ops_init+0x313/0x430 net/core/net_namespace.c:140 setup_net+0x35b/0x9d0 net/core/net_namespace.c:326 copy_net_ns+0x359/0x5c0 net/core/net_namespace.c:470 create_new_namespaces+0x4ce/0xa00 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0x11e/0x180 kernel/nsproxy.c:226 ksys_unshare+0x57d/0xb50 kernel/fork.c:3075 __do_sys_unshare kernel/fork.c:3146 [inline] __se_sys_unshare kernel/fork.c:3144 [inline] __x64_sys_unshare+0x34/0x40 kernel/fork.c:3144 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f66c882ce99 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f66c71a2168 EFLAGS: 00000246 ORIG_RAX: 0000000000000110 RAX: ffffffffffffffda RBX: 00007f66c893ff60 RCX: 00007f66c882ce99 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000048040200 RBP: 00007f66c8886ff1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fff6634832f R14: 00007f66c71a2300 R15: 0000000000022000 </TASK>

CVSS metrics

5 scores · 4 sources · 2 versions

EPSS trend

Probability

0.26%

Chance of exploitation in the next 30 days

Percentile

18%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.26% 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

No weakness data has been published for this record.

Affected systems

Version check

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

Ubuntu87 products
  • linux< 4.15.0-169.177 | < 5.4.0-105.119
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-aws< 4.15.0-1121.129 | < 5.4.0-1069.73
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Linux2 products
  • linux≥ cf124db566e6b036b8bcbe8decbed740bdfac8c6, < 4e1797914d8f223726ff6ae5ece4f97d73f21bab | ≥ cf124db566e6b036b8bcbe8decbed740bdfac8c6, < e56b65c1e74d7f706d74b51baba15187be2fb4b5 | ≥ cf124db566e6b036b8bcbe8decbed740bdfac8c6, < ad0ed314d6167b212939e3839428ba0c8bb16adb | ≥ cf124db566e6b036b8bcbe8decbed740bdfac8c6, < 6f46c59e60b64620d5d386c8ee2eaa11ebe3b595 | ≥ cf124db566e6b036b8bcbe8decbed740bdfac8c6, < 44a6c846bc3a7efe7d394bab8b2ae3b7f580e190 | ≥ cf124db566e6b036b8bcbe8decbed740bdfac8c6, < e28587cc491ef0f3c51258fdc87fbc386b1d4c59 | 95876855a55072572895a236b156ffb357fd5538 | ≥ 4.11.9, < 4.12 | 4.12
  • linux_kernel≥ 4.11.9, < 4.12 | ≥ 4.12.1, < 4.14.259 | ≥ 4.15, < 4.19.222 | ≥ 4.20, < 5.4.168 | ≥ 5.5, < 5.10.88 | ≥ 5.11, < 5.15.11 | 4.12 | 4.12:rc6 | 4.12:rc7 | 5.16:rc1 | 5.16:rc2 | 5.16:rc3 | 5.16:rc4 | 5.16:rc5
Debian1 product
  • linux< 5.15.15-1

3 vendors · 90 products

References

10 links