What’s Vulnerable › Vulnerabilities

CVE-2025-21844: smb: client: Add check for next_buffer in receive_encrypted_standard()

• Severity: medium (CVSS 5.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.6% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2025-03-12 · updated 2026-10-15
• Weakness: CWE-476

Description

In the Linux kernel, the following vulnerability has been resolved: smb: client: Add check for next_buffer in receive_encrypted_standard() Add check for the return value of cifs_buf_get() and cifs_small_buf_get() in receive_encrypted_standard() to prevent null pointer dereference.

Affected products

• Linux kernel: from 6.1.69 before 6.1.130; from 6.6.8 before 6.6.80; from 6.7 before 6.12.17; from 6.13 before 6.13.5; 5.10.211, 5.15.150, 6.14-rc1, 6.14-rc2, 6.14-rc3 — fixed in 6.1.130, 6.12.17, 6.13.5, 6.6.80

How to fix

Upgrade to a fixed version: Linux kernel 6.1.130, 6.12.17, 6.13.5, 6.6.80. Check the vendor advisory for mitigations.

References

• https://git.kernel.org/stable/c/24e8e4523d3071bc5143b0db9127d511489f7b3b
• https://git.kernel.org/stable/c/554736b583f529ee159aa95af9a0cbc12b5ffc96
• https://git.kernel.org/stable/c/860ca5e50f73c2a1cef7eefc9d39d04e275417f7
• https://git.kernel.org/stable/c/9e5d99a4cf2e23c716b44862975548415fae5391
• https://git.kernel.org/stable/c/a9b0b4b29877cb4dc5d0842b59b5ccbacddb85bd
• https://git.kernel.org/stable/c/f277e479eea3d1aa18bc712abe1d2bf3dece2e30
• https://git.kernel.org/stable/c/f618aeb6cad2307e48a641379db610abcf593edf
• https://lists.debian.org/debian-lts-announce/2025/05/msg00030.html
• https://lists.debian.org/debian-lts-announce/2025/05/msg00045.html
• https://cert-portal.siemens.com/productcert/html/ssa-265688.html
• https://cert-portal.siemens.com/productcert/html/ssa-784472.html

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