CVE-2025-37778: debian linux Use-After-Free — Fix

Description

In the Linux kernel, the following vulnerability has been resolved: ksmbd: Fix dangling pointer in krb_authenticate krb_authenticate frees sess->user and does not set the pointer to NULL. It calls ksmbd_krb5_authenticate to reinitialise sess->user but that function may return without doing so. If that happens then smb2_sess_setup, which calls krb_authenticate, will be accessing free'd memory when it later uses sess->user.

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CVSS v3.1 Score

7.8

HIGH

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

Weakness Type (CWE)

CWE-416 Use After Free

Affected Products

Vendor	Product	Versions
linux	linux_kernel	5.15 — 6.1.135
linux	linux_kernel	6.2 — 6.6.88
linux	linux_kernel	6.7 — 6.12.25
linux	linux_kernel	6.13 — 6.14.4
linux	linux_kernel	All
linux	linux_kernel	All
debian	debian_linux	All

References

Advisories & Patches

https://git.kernel.org/stable/c/1db2451de23e98bc864c6a6e52aa0d82c91cb325 https://git.kernel.org/stable/c/1e440d5b25b7efccb3defe542a73c51005799a5f https://git.kernel.org/stable/c/6e30c0e10210c714f3d4453dc258d4abcc70364e https://git.kernel.org/stable/c/d5b554bc8d554ed6ddf443d3db2fad9f665cec10 https://git.kernel.org/stable/c/e83e39a5f6a01a81411a4558a59a10f87aa88dd6

Other References

https://git.kernel.org/stable/c/b61f04d5d73c53d183019bafe22fb700a739bac5 https://lists.debian.org/debian-lts-announce/2025/05/msg00045.html

Frequently Asked Questions

What is CVE-2025-37778? +

In the Linux kernel, the following vulnerability has been resolved: ksmbd: Fix dangling pointer in krb_authenticate krb_authenticate frees sess->user and does not set the pointer to NULL. It calls ksmbd_krb5_authenticate to reinitialise sess->user but that function may return without doing so. If that happens then smb2_sess_setup, which calls krb_authenticate, will be accessing free'd memory when it later uses sess->user. It has a CVSS v3.1 base score of 7.8 (HIGH).

How severe is CVE-2025-37778? +

CVE-2025-37778 has a CVSS v3.1 score of 7.8 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching.

What products are affected by CVE-2025-37778? +

CVE-2025-37778 affects products from debian, linux, specifically: debian_linux, linux_kernel. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2025-37778? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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