CVE-2025-22003can: ucan: fix out of bound read in strscpy() source
- 5.5MediumCVSS base score
- 0.21%Exploitation in 30 daysEPSS · top 88% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
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 usb_control_msg() returns. With this, the local firmware_str[] variable can be removed. On top of this do a couple refactors: - ucan_ctl_payload->raw is only used for the firmware string, so rename it to ucan_ctl_payload->fw_str and change its type from u8 to char. - ucan_device_request_in() is only used to retrieve the firmware string, so rename it to ucan_get_fw_str() and refactor it to make it directly handle all the string termination logic.
Timeline
ID reserved
By Linux
- 3 months later
· 3 months later
Published
- 13 months later
· 13 months later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| CISA-ADPADP (enrichment) | 3.1 | Medium5.5 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
| NVDNVD · Modified | 3.1 | Medium5.5 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
- EPSS (exploitation in 30 days)
- 0.21% · top 88% of all CVEs (14 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.5.
Affected products
- affected 7fdaf8966aae476deafe11f9a0067ff588615444 – < cc29775a8a72d7f3b56cc026796ad99bd65804a7
- affected 7fdaf8966aae476deafe11f9a0067ff588615444 – < 8cec9e314d3360fc1d8346297c41a6ee45cb45a9
- affected 7fdaf8966aae476deafe11f9a0067ff588615444 – < a4994161a61bc8fd71d105c579d847cefee99262
- affected 7fdaf8966aae476deafe11f9a0067ff588615444 – < 1d22a122ffb116c3cf78053e812b8b21f8852ee9
- affected 6.2
- unaffected < 6.2
- unaffected 6.6.85 – ≤ 6.6.*
- unaffected 6.12.21 – ≤ 6.12.*
- unaffected 6.13.9 – ≤ 6.13.*
- unaffected 6.14 – ≤ *
References
References4
- https://git.kernel.org/stable/c/cc29775a8a72d7f3b56cc026796ad99bd65804a7 (opens in a new tab)
- https://git.kernel.org/stable/c/8cec9e314d3360fc1d8346297c41a6ee45cb45a9 (opens in a new tab)
- https://git.kernel.org/stable/c/a4994161a61bc8fd71d105c579d847cefee99262 (opens in a new tab)
- https://git.kernel.org/stable/c/1d22a122ffb116c3cf78053e812b8b21f8852ee9 (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2025-9600 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2025-22003)Record last updated .