NVD / CVE Program· CNA Linux

CVE-2024-27394: tcp: Fix Use-After-Free in tcp_ao_connect_init

HighCVSS 7.8 · v3.1—No exploit Fix available

Noroxi assessment

Priority: Monitor (action score 31/100)

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: 0.26% (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 80e679b352c3ce5158f3f778cfb77eb767e586fb, ca4fb6c6764b3f75b4f5aa81db1536291897ff7f.

Low priority for now. Upgrade to Linux Linux 80e679b352c3ce5158f3f778cfb77eb767e586fb, ca4fb6c6764b3f75b4f5aa81db1536291897ff7f 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: tcp: Fix Use-After-Free in tcp_ao_connect_init Since call_rcu, which is called in the hlist_for_each_entry_rcu traversal of tcp_ao_connect_init, is not part of the RCU read critical section, it is possible that the RCU grace period will pass during the traversal and the key will be free. To prevent this, it should be changed to hlist_for_each_entry_safe.

Memory safety

BDU:2024-03938

Published: May 14, 2024
Updated: Aug 5, 2026
EPSS: 0.2% · 18th percentile
CWE: CWE-416

Report tools

JSON

Action score

Monitor

Low priority for now.

CVSS: 31 / 40 · 7.8 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.2%

CISA SSVC decision

Exploitation: proof of concept
Automatable: no
Technical impact: total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD: —
CNA · Linux: 7.8; NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

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.

Is your version affected? Check it

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.

Vendor	Product	CPE
linux	linux kernel	cpe:2.3:o:linux:linux_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
- 6.7affected
- 7c2ffaf21bd67f73d21560995ce17eaf5fc1d37f and later · before ca4fb6c6764b3f75b4f5aa81db1536291897ff7faffected · git
- 7c2ffaf21bd67f73d21560995ce17eaf5fc1d37f and later · before 80e679b352c3ce5158f3f778cfb77eb767e586fbaffected · git
- before 6.7not affected · semver
- 6.8.9 and later · up to and including 6.8.*not affected · semver
- 6.9 and laternot affected · original_commit_for_fix

Affected versions

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

linux linux kernel6.7 and later · before 6.8.9
linux linux kernel6.9

Package-level exposure

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

Ecosystem	Package	Affected range	Fix
Debian:13	linux	before 6.8.9-1	6.8.9-1

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-2023-52656May 14, 2024 · io_uring: drop any code related to SCM_RIGHTS
22Monitor
← EarlierCVE-2024-27393May 14, 2024 · xen-netfront: Add missing skb_mark_for_recycle
30Monitor
Later →CVE-2024-27398May 14, 2024 · Bluetooth: Fix use-after-free bugs caused by sco_sock_timeout
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 / package	Fixed version	Source
Linux Linux	80e679b352c3ce5158f3f778cfb77eb767e586fb	Vendor (CNA)
Linux Linux	ca4fb6c6764b3f75b4f5aa81db1536291897ff7f	Vendor (CNA)
debian:linux	6.8.9-1 · Debian:13	Package 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.

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: high · data can be read
Integrity: high · data or configuration can be modified
Availability: high · the service can be disrupted

Attack vector: Local
Attack complexity: Low
Privileges required: Low
User interaction: None
Scope: Unchanged
Confidentiality impact: High
Integrity impact: High
Availability impact: High

Weakness class (CWE)

CWE-416 · Use After Free

CVSS vector

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

nvd-secondary

Root cause

After a memory region is freed, another reference pointing to it is still used. By then, the same region may have been allocated for different data.

The bug in code

The whole CWE-416 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

1free(dev->buf);
2/* ... another thread is still running ... */
3process(dev->buf);

Fixed

1lock(&dev->lock);
2free(dev->buf);
3dev->buf = NULL;
4unlock(&dev->lock);

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.

Change log (1)

Fix✗ → ✓Sep 28, 2026, 10:08 PM UTC

For records you follow, these changes also arrive as notifications. →

References

git.kernel.org/stable/c/80e679b352c3ce5158f3f778cfb77eb767e586fb

Show all references (1 more)

git.kernel.org/stable/c/ca4fb6c6764b3f75b4f5aa81db1536291897ff7f

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

All records