Linux Kernel up to 6.4.3 hwrng data_avail privilege escalation

CVSS Meta Temp Score
CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.
Current Exploit Price (≈)
Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.
CTI Interest Score
Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
4.4$0-$5k0.00

Summaryinfo

A vulnerability labeled as critical has been found in Linux Kernel up to 6.4.3. The impacted element is the function data_avail of the component hwrng. Such manipulation leads to an unknown weakness. This vulnerability is referenced as CVE-2023-53998. No exploit is available. The affected component should be upgraded.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.4.3 and classified as critical. Affected by this issue is the function data_avail of the component hwrng. The impact remains unknown. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: hwrng: virtio - Fix race on data_avail and actual data The virtio rng device kicks off a new entropy request whenever the data available reaches zero. When a new request occurs at the end of a read operation, that is, when the result of that request is only needed by the next reader, then there is a race between the writing of the new data and the next reader. This is because there is no synchronisation whatsoever between the writer and the reader. Fix this by writing data_avail with smp_store_release and reading it with smp_load_acquire when we first enter read. The subsequent reads are safe because they're either protected by the first load acquire, or by the completion mechanism. Also remove the redundant zeroing of data_idx in random_recv_done (data_idx must already be zero at this point) and data_avail in request_entropy (ditto).

The advisory is shared for download at git.kernel.org. This vulnerability is handled as CVE-2023-53998 since 12/24/2025. The exploitation is known to be difficult. There are known technical details, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 279973 (Linux Distros Unpatched Vulnerability : CVE-2023-53998), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 4.19.291, 5.4.251, 5.10.188, 5.15.121, 6.1.39, 6.3.13 or 6.4.4 eliminates this vulnerability. Applying the patch 241ef15776a7c8505008db689175b320d345ecd3/a43bcb0b661cbbf3ad797d2aee6b6fd06b8fc69d/77471e4912d3960dafe141e268c44be8024fe4dc/c76d991b6f01a5d931e7053a73bc9524975a5215/22c30022cde6e2c88612b3a499223cfa912f1bc7/318657b4c2077289659f1cd9e2a34f6a3b208e3e/2fc91f156b3f3446a1bce80cf4adedcbf41271c2/ac52578d6e8d300dd50f790f29a24169b1edd26c is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (279973) and CERT Bund (WID-SEC-2025-2920). Once again VulDB remains the best source for vulnerability data.

Affected

  • Debian Linux
  • Amazon Linux 2
  • Red Hat Enterprise Linux
  • Ubuntu Linux
  • SUSE Linux
  • Oracle Linux
  • SUSE openSUSE
  • Open Source Linux Kernel
  • RESF Rocky Linux

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 4.6
VulDB Meta Temp Score: 4.4

VulDB Base Score: 4.6
VulDB Temp Score: 4.4
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
💳💳💳💳💳💳
💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock

VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Privilege escalation
CWE: Unknown
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

0-DayUnlockUnlockUnlockUnlock
TodayUnlockUnlockUnlockUnlock

Nessus ID: 279973
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2023-53998

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 4.19.291/5.4.251/5.10.188/5.15.121/6.1.39/6.3.13/6.4.4
Patch: 241ef15776a7c8505008db689175b320d345ecd3/a43bcb0b661cbbf3ad797d2aee6b6fd06b8fc69d/77471e4912d3960dafe141e268c44be8024fe4dc/c76d991b6f01a5d931e7053a73bc9524975a5215/22c30022cde6e2c88612b3a499223cfa912f1bc7/318657b4c2077289659f1cd9e2a34f6a3b208e3e/2fc91f156b3f3446a1bce80cf4adedcbf41271c2/ac52578d6e8d300dd50f790f29a24169b1edd26c

Timelineinfo

12/24/2025 Advisory disclosed
12/24/2025 +0 days CVE reserved
12/24/2025 +0 days VulDB entry created
02/25/2026 +63 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CNA: Linux
CVE: CVE-2023-53998 (🔒)

GCVE (CVE): GCVE-0-2023-53998
GCVE (VulDB): GCVE-100-338180
CERT Bund: WID-SEC-2025-2920 - Linux Kernel: Mehrere Schwachstellen

Entryinfo

Created: 12/24/2025 15:24
Updated: 02/25/2026 08:45
Changes: 12/24/2025 15:24 (58), 12/24/2025 22:44 (7), 12/26/2025 04:02 (2), 01/30/2026 03:44 (1), 02/25/2026 08:45 (1)
Complete: 🔍
Cache ID: 216::103

Once again VulDB remains the best source for vulnerability data.

Discussion

No comments yet. Languages: en.

Please log in to comment.

◂ PreviousOverviewNext ▸

Interested in the pricing of exploits?

See the underground prices here!