CVE-2025-22003

Source
https://nvd.nist.gov/vuln/detail/CVE-2025-22003
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-22003.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2025-22003
Downstream
Related
Published
2025-04-03T08:15:15Z
Modified
2025-04-10T16:13:15Z
Severity
  • 5.5 (Medium) CVSS_V3 - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
Summary
[none]
Details

In the Linux kernel, the following vulnerability has been resolved:

can: ucan: fix out of bound read in strscpy() source

Commit 7fdaf8966aae ("can: ucan: use strscpy() to instead of strncpy()") unintentionally introduced a one byte out of bound read on strscpy()'s source argument (which is kind of ironic knowing that strscpy() is meant to be a more secure alternative :)).

Let's consider below buffers:

dest[len + 1]; /* will be NUL terminated / src[len]; / may not be NUL terminated */

When doing:

strncpy(dest, src, len); dest[len] = '\0';

strncpy() will read up to len bytes from src.

On the other hand:

strscpy(dest, src, len + 1);

will read up to len + 1 bytes from src, that is to say, an out of bound read of one byte will occur on src if it is not NUL terminated. Note that the src[len] byte is never copied, but strscpy() still needs to read it to check whether a truncation occurred or not.

This exact pattern happened in ucan.

The root cause is that the source is not NUL terminated. Instead of doing a copy in a local buffer, directly NUL terminate it as soon as usbcontrolmsg() returns. With this, the local firmware_str[] variable can be removed.

On top of this do a couple refactors:

  • ucanctlpayload->raw is only used for the firmware string, so rename it to ucanctlpayload->fw_str and change its type from u8 to char.

  • ucandevicerequestin() is only used to retrieve the firmware string, so rename it to ucangetfwstr() and refactor it to make it directly handle all the string termination logic.

References

Affected packages

Debian:13 / linux

Package

Name
linux
Purl
pkg:deb/debian/linux?arch=source

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
6.12.21-1

Ecosystem specific

{
    "urgency": "not yet assigned"
}