NVD / CVE Program· CNA Linux

CVE-2023-53219: media: netup_unidvb: fix use-after-free at del_timer()

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: 0.16% (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 051af3f0b7d1cd8ab7f3e2523ad8ae1af44caba3, 07821524f67bf920342bc84ae8b3dea2a315a89e, 0f5bb36bf9b39a2a96e730bf4455095b50713f63.

Low priority for now. Upgrade to Linux Linux 051af3f0b7d1cd8ab7f3e2523ad8ae1af44caba3, 07821524f67bf920342bc84ae8b3dea2a315a89e, 0f5bb36bf9b39a2a96e730bf4455095b50713f63 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: media: netup_unidvb: fix use-after-free at del_timer() When Universal DVB card is detaching, netup_unidvb_dma_fini() uses del_timer() to stop dma->timeout timer. But when timer handler netup_unidvb_dma_timeout() is running, del_timer() could not stop it. As a result, the use-after-free bug could happen. The process is shown below: (cleanup routine) | (timer routine) | mod_timer(&dev->tx_sim_timer, ..) netup_unidvb_finidev() | (wait a time) netup_unidvb_dma_fini() | netup_unidvb_dma_timeout() del_timer(&dma->timeout); | | ndev->pci_dev->dev //USE Fix by changing del_timer() to del_timer_sync().

HighCVSS 7.8 · v3.1—No exploit Fix available

Memory safety

BDU:2026-08829

Published: Sep 15, 2025
Updated: Aug 5, 2026
EPSS: 0.1% · 5th percentile
CWE: CWE-416

Report tools

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Action score

Monitor

Low priority for now.

CVSS: 31 / 40 · 7.8 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.1%

CISA SSVC decision

Exploitation: none
Automatable: no
Technical impact: total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD: 7.8
CNA · Linux: 7.8; agree

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

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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.

Vendor	Product	CPE
linux	linux kernel	cpe:2.3:o:linux:linux_kernel

Affected versions

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

linux linux kernel4.3 and later · before 4.14.316
linux linux kernel4.15 and later · before 4.19.284
linux linux kernel4.20 and later · before 5.4.244
linux linux kernel5.5 and later · before 5.10.181
linux linux kernel5.11 and later · before 5.15.113
linux linux kernel5.16 and later · before 6.1.30
linux linux kernel6.2 and later · before 6.3.4
linux linux kernel6.4

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
- 4.3affected
- 52b1eaf4c59a3bbd07afbb4ab4f43418a807d02e and later · before dd5c77814f290b353917df329f36de1472d47154affected · git
- 52b1eaf4c59a3bbd07afbb4ab4f43418a807d02e and later · before 90229e9ee957d4514425e4a4d82c50ab5d57ac4daffected · git
- 52b1eaf4c59a3bbd07afbb4ab4f43418a807d02e and later · before 1550bcf2983ae1220cc8ab899a39a423fa7cb523affected · git
- 52b1eaf4c59a3bbd07afbb4ab4f43418a807d02e and later · before f9982db735a8495eee14267cf193c806b957e942affected · git
- 52b1eaf4c59a3bbd07afbb4ab4f43418a807d02e and later · before 051af3f0b7d1cd8ab7f3e2523ad8ae1af44caba3affected · git
- 52b1eaf4c59a3bbd07afbb4ab4f43418a807d02e and later · before 07821524f67bf920342bc84ae8b3dea2a315a89eaffected · git
- 52b1eaf4c59a3bbd07afbb4ab4f43418a807d02e and later · before c8f9c05e1ebcc9c7bc211cc8b74d8fb86a8756fcaffected · git
- 52b1eaf4c59a3bbd07afbb4ab4f43418a807d02e and later · before 0f5bb36bf9b39a2a96e730bf4455095b50713f63affected · git
- before 4.3not affected · semver

Package-level exposure

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

Ecosystem	Package	Affected range	Fix
Debian:12	linux	before 6.1.37-1	6.1.37-1
Debian:13	linux	before 6.3.7-1	6.3.7-1

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-2023-53217Sep 15, 2025 · nubus: Partially revert proc_create_single_data() conversion
31Monitor
← EarlierCVE-2023-53218Sep 15, 2025 · rxrpc: Make it so that a waiting process can be aborted
31Monitor
Later →CVE-2023-53220Sep 15, 2025 · media: az6007: Fix null-ptr-deref in az6007_i2c_xfer()
22Monitor

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	051af3f0b7d1cd8ab7f3e2523ad8ae1af44caba3	Vendor (CNA)
Linux Linux	07821524f67bf920342bc84ae8b3dea2a315a89e	Vendor (CNA)
Linux Linux	0f5bb36bf9b39a2a96e730bf4455095b50713f63	Vendor (CNA)
Linux Linux	1550bcf2983ae1220cc8ab899a39a423fa7cb523	Vendor (CNA)
Linux Linux	90229e9ee957d4514425e4a4d82c50ab5d57ac4d	Vendor (CNA)
Linux Linux	c8f9c05e1ebcc9c7bc211cc8b74d8fb86a8756fc	Vendor (CNA)
Linux Linux	dd5c77814f290b353917df329f36de1472d47154	Vendor (CNA)
Linux Linux	f9982db735a8495eee14267cf193c806b957e942	Vendor (CNA)
debian:linux	6.1.37-1 · Debian:12	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.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

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-primary

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

Fix✗ → ✓Sep 28, 2026, 10:09 PM UTC

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

References

git.kernel.org/stable/c/051af3f0b7d1cd8ab7f3e2523ad8ae1af44caba3

Show all references (7 more)

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

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