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NVD / CVE Program· CNA Linux

CVE-2021-47250: net: ipv4: fix memory leak in netlbl_cipsov4_add_std

MediumCVSS 5.5 · v3.1—No exploit Fix available

Noroxi assessment

Priority: Monitor (action score 22/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.23% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux 086e92b1d68c6338535f715aad173f8cf4bfbc8c, 0ffb460be3abac86f884a8c548bb02724ec370f4, 212166510582631994be4f4b3fe15e10a03c1dd4.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 086e92b1d68c6338535f715aad173f8cf4bfbc8c, 0ffb460be3abac86f884a8c548bb02724ec370f4, 212166510582631994be4f4b3fe15e10a03c1dd4 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In the Linux kernel, the following vulnerability has been resolved: net: ipv4: fix memory leak in netlbl_cipsov4_add_std Reported by syzkaller: BUG: memory leak unreferenced object 0xffff888105df7000 (size 64): comm "syz-executor842", pid 360, jiffies 4294824824 (age 22.546s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<00000000e67ed558>] kmalloc include/linux/slab.h:590 [inline] [<00000000e67ed558>] kzalloc include/linux/slab.h:720 [inline] [<00000000e67ed558>] netlbl_cipsov4_add_std net/netlabel/netlabel_cipso_v4.c:145 [inline] [<00000000e67ed558>] netlbl_cipsov4_add+0x390/0x2340 net/netlabel/netlabel_cipso_v4.c:416 [<0000000006040154>] genl_family_rcv_msg_doit.isra.0+0x20e/0x320 net/netlink/genetlink.c:739 [<00000000204d7a1c>] genl_family_rcv_msg net/netlink/genetlink.c:783 [inline] [<00000000204d7a1c>] genl_rcv_msg+0x2bf/0x4f0 net/netlink/genetlink.c:800 [<00000000c0d6a995>] netlink_rcv_skb+0x134/0x3d0 net/netlink/af_netlink.c:2504 [<00000000d78b9d2c>] genl_rcv+0x24/0x40 net/netlink/genetlink.c:811 [<000000009733081b>] netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline] [<000000009733081b>] netlink_unicast+0x4a0/0x6a0 net/netlink/af_netlink.c:1340 [<00000000d5fd43b8>] netlink_sendmsg+0x789/0xc70 net/netlink/af_netlink.c:1929 [<000000000a2d1e40>] sock_sendmsg_nosec net/socket.c:654 [inline] [<000000000a2d1e40>] sock_sendmsg+0x139/0x170 net/socket.c:674 [<00000000321d1969>] ____sys_sendmsg+0x658/0x7d0 net/socket.c:2350 [<00000000964e16bc>] ___sys_sendmsg+0xf8/0x170 net/socket.c:2404 [<000000001615e288>] __sys_sendmsg+0xd3/0x190 net/socket.c:2433 [<000000004ee8b6a5>] do_syscall_64+0x37/0x90 arch/x86/entry/common.c:47 [<00000000171c7cee>] entry_SYSCALL_64_after_hwframe+0x44/0xae The memory of doi_def->map.std pointing is allocated in netlbl_cipsov4_add_std, but no place has freed it. It should be freed in cipso_v4_doi_free which frees the cipso DOI resource.

Published
May 21, 2024
Updated
Jun 17, 2026
EPSS
0.2% · 15th percentile

Report tools

JSON

Action score

22

Monitor

Low priority for now.

CVSS
22 / 40 · 5.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.2%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
linuxlinux kernel

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 2.6.19affected
    • 96cb8e3313c7a12e026c1ed510522ae6f6023875 and later · before 212166510582631994be4f4b3fe15e10a03c1dd4affected · git
    • 96cb8e3313c7a12e026c1ed510522ae6f6023875 and later · before 086e92b1d68c6338535f715aad173f8cf4bfbc8caffected · git
    • 96cb8e3313c7a12e026c1ed510522ae6f6023875 and later · before 6dcea66d3bb519b426282588f38e884e07893c1faffected · git
    • 96cb8e3313c7a12e026c1ed510522ae6f6023875 and later · before 5340858147e3dc60913fb3dd0cbb758ec4a26e66affected · git
    • 96cb8e3313c7a12e026c1ed510522ae6f6023875 and later · before 398a24447eb60f060c8994221cb5ae6caf355fa1affected · git
    • 96cb8e3313c7a12e026c1ed510522ae6f6023875 and later · before deeeb65c6ee404f2d1fb80b38b2730645c0f4663affected · git
    • 96cb8e3313c7a12e026c1ed510522ae6f6023875 and later · before 0ffb460be3abac86f884a8c548bb02724ec370f4affected · git
    • 96cb8e3313c7a12e026c1ed510522ae6f6023875 and later · before d612c3f3fae221e7ea736d196581c2217304bbbcaffected · git
    • before 2.6.19not affected · semver
Affected versions · NVD (8)

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • linux linux kernel2.6.19 and later · before 4.4.274
  • linux linux kernel4.5 and later · before 4.9.274
  • linux linux kernel4.10 and later · before 4.14.238
  • linux linux kernel4.15 and later · before 4.19.196
  • linux linux kernel4.20 and later · before 5.4.128
  • linux linux kernel5.5 and later · before 5.10.46
  • linux linux kernel5.11 and later · before 5.12.13
  • linux linux kernel5.13

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 5.10.46-15.10.46-1
SUSE:Linux Enterprise Server 12 SP5kernel-azurebefore 4.12.14-16.188.14.12.14-16.188.1
SUSE:Linux Enterprise Server 12 SP5kernel-source-azurebefore 4.12.14-16.188.14.12.14-16.188.1
SUSE:Linux Enterprise Server 12 SP5kernel-syms-azurebefore 4.12.14-16.188.14.12.14-16.188.1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
    90Now
  • CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe…KEV
    89Now
  • CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
    85Now

Published before and after this one in the same product

  • ← EarlierCVE-2021-47248May 21, 2024 · udp: fix race between close() and udp_abort()
    18Monitor
  • ← EarlierCVE-2021-47249May 21, 2024 · net: rds: fix memory leak in rds_recvmsg
    22Monitor
  • Later →CVE-2021-47251May 21, 2024 · mac80211: fix skb length check in ieee80211_scan_rx()
    31Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux086e92b1d68c6338535f715aad173f8cf4bfbc8cVendor (CNA)
Linux Linux0ffb460be3abac86f884a8c548bb02724ec370f4Vendor (CNA)
Linux Linux212166510582631994be4f4b3fe15e10a03c1dd4Vendor (CNA)
Linux Linux398a24447eb60f060c8994221cb5ae6caf355fa1Vendor (CNA)
Linux Linux5340858147e3dc60913fb3dd0cbb758ec4a26e66Vendor (CNA)
Linux Linux6dcea66d3bb519b426282588f38e884e07893c1fVendor (CNA)
Linux Linuxd612c3f3fae221e7ea736d196581c2217304bbbcVendor (CNA)
Linux Linuxdeeeb65c6ee404f2d1fb80b38b2730645c0f4663Vendor (CNA)
debian:linux5.10.46-1 · Debian:12Package registry (OSV)
suse:kernel-azure4.12.14-16.188.1 · SUSE:Linux Enterprise Server 12 SP5Package registry (OSV)
suse:kernel-source-azure4.12.14-16.188.1 · SUSE:Linux Enterprise Server 12 SP5Package registry (OSV)
suse:kernel-syms-azure4.12.14-16.188.1 · SUSE:Linux Enterprise Server 12 SP5Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

Not on record for this CVE: EPSS history · patch commit or PR link · researcher credit · variant or chain candidate · public bounty program.

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

CWE-401 · Missing Release of Memory after Effective Lifetime

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

References

Show all references (7 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records