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TI-2021-21813 Aliases CVE-2021-47152GHSA-ffg6-3wfr-47xc

mptcp: fix data stream corruption

Priority LOW 34CWE-787Published · Updated

Key facts

Attack vector
Local
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
Code execution
Confidentiality · integrity · availability
High · High · High
Fix status
Partial Red Hat: 1 without a fix

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-787 and the CVSS impact.

Summary

In the Linux kernel, the following vulnerability has been resolved: mptcp: fix data stream corruption Maxim reported several issues when forcing a TCP transparent proxy to use the MPTCP protocol for the inbound connections. He also provided a clean reproducer. The problem boils down to 'mptcp_frag_can_collapse_to()' assuming that only MPTCP will use the given page_frag. If others - e.g. the plain TCP protocol - allocate page fragments, we can end-up re-using already allocated memory for mptcp_data_frag. Fix the issue ensuring that the to-be-expanded data fragment is located at the current page frag end. v1 -> v2: - added missing fixes tag (Mat)

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00243 15th percentileScored 2026-11-07
Fix Partial Linux (Linux): 5.10.42, 5.12.9, 5.13Red Hat: 1 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
LinuxLinux5.7 and later5.10.42, 5.12.9, 5.13Patch availableCNA
  • Linux VendorLinux Affected 5.7 and later Fixed in 5.10.42, 5.12.9, 5.13 Patch available CNA

CPE configurations NVD · 4

CPEVersionsRoleVendor
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*5.7 to before 5.10.42; 5.11 to before 5.12.9VulnerableLinux
cpe:2.3:o:linux:linux_kernel:5.13:rc1:*:*:*:*:*:*5.13 rc1VulnerableLinux
cpe:2.3:o:linux:linux_kernel:5.13:rc2:*:*:*:*:*:*5.13 rc2VulnerableLinux
cpe:2.3:o:linux:linux_kernel:5.13:rc3:*:*:*:*:*:*5.13 rc3VulnerableLinux
  • cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 5.7 to before 5.10.42; 5.11 to before 5.12.9 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:5.13:rc1:*:*:*:*:*:* Versions 5.13 rc1 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:5.13:rc2:*:*:*:*:*:* Versions 5.13 rc2 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:5.13:rc3:*:*:*:*:*:* Versions 5.13 rc3 Vulnerable ·Linux

Remediation

  • Fix · CNA Linux (Linux) Fixed in 5.10.42, 5.12.9, 5.13

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux 8AffectedNo fix planned: Will not fix
Not affected: 4 products
  • Red Hat Enterprise Linux 6
  • Red Hat Enterprise Linux 7
  • Red Hat Enterprise Linux 8
  • Red Hat Enterprise Linux 9

Timeline

  1. 2026-10-02 Threatist record created from CVE-2021-47152
  2. 2026-10-03 Alias added: GHSA-ffg6-3wfr-47xc

References

  • TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
  • TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
  • TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
  • TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
  • TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
  • TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
See all 15278 →

Sources