CVE-2021-47475
What it is
In the Linux kernel, the following vulnerability has been resolved: comedi: vmk80xx: fix transfer-buffer overflows The driver uses endpoint-sized USB transfer buffers but up until recently had no sanity checks on the sizes. Commit e1f13c879a7c ("staging: comedi: check validity of wMaxPacketSize of usb endpoints found") inadvertently fixed NULL-pointer dereferences when accessing the transfer buffers in case a malicious device has a zero wMaxPacketSize. Make sure to allocate buffers large enough to handle also the other accesses that are done without a size check (e.g. byte 18 in vmk80xx_cnt_insn_read() for the VMK8061_MODEL) to avoid writing beyond the buffers, for example, when doing descriptor fuzzing. The original driver was for a low-speed device with 8-byte buffers. Support was later added for a device that uses bulk transfers and is presumably a full-speed device with a maximum 64-byte wMaxPacketSize.
At a glance
- Exploitability
- Can be exploited locally on the machine with a low-privilege account. High risk of data exposure, data tampering, service disruption.
- Exploit odds
- 0.3% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.3% in the next 30 days (EPSS).
- Severity: 7.8 HIGH (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.3% · EPSS, next 30 days
- Weakness
- CWE-787 · Out-of-bounds write
- Record status
- Analyzed
Affected
- Linux Kernel < 4.4.292
- Linux Kernel < 4.9.290
- Linux Kernel < 4.14.255
- Linux Kernel < 4.19.217
- Linux Kernel < 5.4.159
- Linux Kernel < 5.10.79
- Linux Kernel < 5.14.18
- Linux Kernel < 5.15.2
Attack profile CVSS 3.1 · 7.8
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Raw vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2021-47475.md and follow it. Check whether this project is affected by CVE-2021-47475. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://git.kernel.org/stable/c/06ac746d57e6d32b062e220415c607b7e2e0fa50
- https://git.kernel.org/stable/c/199acd8c110e3ae62833c24f632b0bb1c9f012a9
- https://git.kernel.org/stable/c/278484ae93297b1bb1ce755f9d3b6d95a48c7d47
- https://git.kernel.org/stable/c/33d7a470730dfe7c9bfc8da84575cf2cedd60d00
- https://git.kernel.org/stable/c/40d2a7e278e2e7c0a5fd7e997e7eb63945bf93f7
- https://git.kernel.org/stable/c/5229159f1d052821007aff1a1beb7873eacf1a9f
- https://git.kernel.org/stable/c/7a2021b896de1ad559d33b5c5cdd20b982242088
- https://git.kernel.org/stable/c/a23461c47482fc232ffc9b819539d1f837adf2b1
- https://git.kernel.org/stable/c/ec85bcff4ed09260243d8f39faba99e1041718ba
- https://git.kernel.org/stable/c/06ac746d57e6d32b062e220415c607b7e2e0fa50
References
- https://git.kernel.org/stable/c/06ac746d57e6d32b062e220415c607b7e2e0fa50
- https://git.kernel.org/stable/c/199acd8c110e3ae62833c24f632b0bb1c9f012a9
- https://git.kernel.org/stable/c/278484ae93297b1bb1ce755f9d3b6d95a48c7d47
- https://git.kernel.org/stable/c/33d7a470730dfe7c9bfc8da84575cf2cedd60d00
- https://git.kernel.org/stable/c/40d2a7e278e2e7c0a5fd7e997e7eb63945bf93f7
- https://git.kernel.org/stable/c/5229159f1d052821007aff1a1beb7873eacf1a9f
- https://git.kernel.org/stable/c/7a2021b896de1ad559d33b5c5cdd20b982242088
- https://git.kernel.org/stable/c/a23461c47482fc232ffc9b819539d1f837adf2b1
- https://git.kernel.org/stable/c/ec85bcff4ed09260243d8f39faba99e1041718ba
- https://git.kernel.org/stable/c/06ac746d57e6d32b062e220415c607b7e2e0fa50
- https://git.kernel.org/stable/c/199acd8c110e3ae62833c24f632b0bb1c9f012a9
- https://git.kernel.org/stable/c/278484ae93297b1bb1ce755f9d3b6d95a48c7d47
- https://git.kernel.org/stable/c/33d7a470730dfe7c9bfc8da84575cf2cedd60d00
- https://git.kernel.org/stable/c/40d2a7e278e2e7c0a5fd7e997e7eb63945bf93f7
- https://git.kernel.org/stable/c/5229159f1d052821007aff1a1beb7873eacf1a9f
- https://git.kernel.org/stable/c/7a2021b896de1ad559d33b5c5cdd20b982242088
- https://git.kernel.org/stable/c/a23461c47482fc232ffc9b819539d1f837adf2b1
- https://git.kernel.org/stable/c/ec85bcff4ed09260243d8f39faba99e1041718ba