Linux Kernel up to 6.3.3 vc_screen.c vcs_write use after free

CVSS Meta Temp Score
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CTI Interest Score
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7.6$0-$5k0.00

Summaryinfo

A vulnerability described as critical has been identified in Linux Kernel up to 6.3.3. Affected is the function vcs_write of the file drivers/tty/vt/vc_screen.c. Executing a manipulation can lead to use after free. This vulnerability is handled as CVE-2023-53747. There is not any exploit available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability has been found in Linux Kernel up to 6.3.3 and classified as critical. This vulnerability affects the function vcs_write of the file drivers/tty/vt/vc_screen.c. The manipulation with an unknown input leads to a use after free vulnerability. The CWE definition for the vulnerability is CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: vc_screen: reload load of struct vc_data pointer in vcs_write() to avoid UAF After a call to console_unlock() in vcs_write() the vc_data struct can be freed by vc_port_destruct(). Because of that, the struct vc_data pointer must be reloaded in the while loop in vcs_write() after console_lock() to avoid a UAF when vcs_size() is called. Syzkaller reported a UAF in vcs_size(). BUG: KASAN: slab-use-after-free in vcs_size (drivers/tty/vt/vc_screen.c:215) Read of size 4 at addr ffff8880beab89a8 by task repro_vcs_size/4119 Call Trace: <TASK> __asan_report_load4_noabort (mm/kasan/report_generic.c:380) vcs_size (drivers/tty/vt/vc_screen.c:215) vcs_write (drivers/tty/vt/vc_screen.c:664) vfs_write (fs/read_write.c:582 fs/read_write.c:564) ... <TASK> Allocated by task 1213: kmalloc_trace (mm/slab_common.c:1064) vc_allocate (./include/linux/slab.h:559 ./include/linux/slab.h:680 drivers/tty/vt/vt.c:1078 drivers/tty/vt/vt.c:1058) con_install (drivers/tty/vt/vt.c:3334) tty_init_dev (drivers/tty/tty_io.c:1303 drivers/tty/tty_io.c:1415 drivers/tty/tty_io.c:1392) tty_open (drivers/tty/tty_io.c:2082 drivers/tty/tty_io.c:2128) chrdev_open (fs/char_dev.c:415) do_dentry_open (fs/open.c:921) vfs_open (fs/open.c:1052) ... Freed by task 4116: kfree (mm/slab_common.c:1016) vc_port_destruct (drivers/tty/vt/vt.c:1044) tty_port_destructor (drivers/tty/tty_port.c:296) tty_port_put (drivers/tty/tty_port.c:312) vt_disallocate_all (drivers/tty/vt/vt_ioctl.c:662 (discriminator 2)) vt_ioctl (drivers/tty/vt/vt_ioctl.c:903) tty_ioctl (drivers/tty/tty_io.c:2778) ... The buggy address belongs to the object at ffff8880beab8800 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 424 bytes inside of freed 1024-byte region [ffff8880beab8800, ffff8880beab8c00) The buggy address belongs to the physical page: page:00000000afc77580 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0xbeab8 head:00000000afc77580 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfffffc0010200(slab|head|node=0|zone=1|lastcpupid=0x1fffff) page_type: 0xffffffff() raw: 000fffffc0010200 ffff888100042dc0 ffffea000426de00 dead000000000002 raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880beab8880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880beab8900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880beab8980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880beab8a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880beab8a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== Disabling lock debugging due to kernel taint

The advisory is shared for download at git.kernel.org. This vulnerability was named CVE-2023-53747 since 12/08/2025. The exploitation appears to be easy. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 02/23/2026).

The vulnerability scanner Nessus provides a plugin with the ID 277787 (Linux Distros Unpatched Vulnerability : CVE-2023-53747), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 4.14.327, 4.19.284, 5.4.244, 5.10.181, 5.15.113, 6.1.30 or 6.3.4 eliminates this vulnerability. Applying the patch 934de9a9b659785fed3e820bc0c813a460c71fea/0deff678157333d775af190f84696336cdcccd6d/a4e3c4c65ae8510e01352c9a4347e05c035b2ce2/11dddfbb7a4e62489b01074d6c04d9d1b42e4047/e3d1adcad5b73c7ed0c7edb35ab68abcaa45cf67/3338d0b9acde770ee588eead5cac32c25e7048fc/1de42e7653d6714a7507ba6696151a1fa028c69f/8fb9ea65c9d1338b0d2bb0a9122dc942cdd32357 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 (277787), EUVD (EUVD-2023-60081) and CERT Bund (WID-SEC-2025-2756). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Affected

  • Google Container-Optimized OS
  • Debian Linux
  • Amazon Linux 2
  • Red Hat Enterprise Linux
  • Ubuntu Linux
  • SUSE Linux
  • Oracle Linux
  • NetApp FAS
  • NetApp AFF
  • SUSE openSUSE
  • RESF Rocky Linux
  • Open Source Linux Kernel
  • Microsoft Azure Linux

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 8.0
VulDB Meta Temp Score: 7.6

VulDB Base Score: 8.0
VulDB Temp Score: 7.6
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
💳💳💳💳💳💳
💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Use after free
CWE: CWE-416 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 277787
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2023-53747

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 4.14.327/4.19.284/5.4.244/5.10.181/5.15.113/6.1.30/6.3.4
Patch: 934de9a9b659785fed3e820bc0c813a460c71fea/0deff678157333d775af190f84696336cdcccd6d/a4e3c4c65ae8510e01352c9a4347e05c035b2ce2/11dddfbb7a4e62489b01074d6c04d9d1b42e4047/e3d1adcad5b73c7ed0c7edb35ab68abcaa45cf67/3338d0b9acde770ee588eead5cac32c25e7048fc/1de42e7653d6714a7507ba6696151a1fa028c69f/8fb9ea65c9d1338b0d2bb0a9122dc942cdd32357

Timelineinfo

12/08/2025 Advisory disclosed
12/08/2025 +0 days CVE reserved
12/08/2025 +0 days VulDB entry created
02/23/2026 +77 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2023-53747 (🔒)
GCVE (CVE): GCVE-0-2023-53747
GCVE (VulDB): GCVE-100-334696
EUVD: 🔒
CERT Bund: WID-SEC-2025-2756 - Linux Kernel: Mehrere Schwachstellen erm&ouml;glichen Denial of Service

Entryinfo

Created: 12/08/2025 06:08
Updated: 02/23/2026 01:30
Changes: 12/08/2025 06:08 (59), 12/08/2025 06:27 (1), 12/08/2025 10:45 (1), 12/09/2025 02:26 (7), 12/09/2025 05:45 (2), 12/24/2025 00:38 (1), 01/04/2026 09:39 (1), 01/22/2026 04:46 (1), 02/23/2026 01:30 (1)
Complete: 🔍
Cache ID: 216::103

VulDB is the best source for vulnerability data and more expert information about this specific topic.

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