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CVE Record

CVE-2025-21708: net: usb: rtl8150: enable basic endpoint checking

In the Linux kernel, the following vulnerability has been resolved: net: usb: rtl8150: enable basic endpoint checking Syzkaller reports [1] encountering a common issue of utilizing a wrong usb endpoint type during URB submitting stage. This, in turn, triggers a warning shown below. For now, enable simple endpoint checking (specifically, bulk and interrupt eps, testing control one is not essential) to mitigate the issue with a view to do other related cosmetic changes later, if they are necessary. [1] Syzkaller report: usb 1-1: BOGUS urb xfer, pipe 3 != type 1 WARNING: CPU: 1 PID: 2586 at drivers/usb/core/urb.c:503 usb_submit_urb+0xe4b/0x1730 driv> Modules linked in: CPU: 1 UID: 0 PID: 2586 Comm: dhcpcd Not tainted 6.11.0-rc4-syzkaller-00069-gfc88bb11617> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 RIP: 0010:usb_submit_urb+0xe4b/0x1730 drivers/usb/core/urb.c:503 Code: 84 3c 02 00 00 e8 05 e4 fc fc 4c 89 ef e8 fd 25 d7 fe 45 89 e0 89 e9 4c 89 f2 48 8> RSP: 0018:ffffc9000441f740 EFLAGS: 00010282 RAX: 0000000000000000 RBX: ffff888112487a00 RCX: ffffffff811a99a9 RDX: ffff88810df6ba80 RSI: ffffffff811a99b6 RDI: 0000000000000001 RBP: 0000000000000003 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000001 R13: ffff8881023bf0a8 R14: ffff888112452a20 R15: ffff888112487a7c FS: 00007fc04eea5740(0000) GS:ffff8881f6300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f0a1de9f870 CR3: 000000010dbd0000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> rtl8150_open+0x300/0xe30 drivers/net/usb/rtl8150.c:733 __dev_open+0x2d4/0x4e0 net/core/dev.c:1474 __dev_change_flags+0x561/0x720 net/core/dev.c:8838 dev_change_flags+0x8f/0x160 net/core/dev.c:8910 devinet_ioctl+0x127a/0x1f10 net/ipv4/devinet.c:1177 inet_ioctl+0x3aa/0x3f0 net/ipv4/af_inet.c:1003 sock_do_ioctl+0x116/0x280 net/socket.c:1222 sock_ioctl+0x22e/0x6c0 net/socket.c:1341 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl fs/ioctl.c:893 [inline] __x64_sys_ioctl+0x193/0x220 fs/ioctl.c:893 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fc04ef73d49 ... This change has not been tested on real hardware.

UnknownCVSS not scoredNot KEV-listedUpdated
Glexia's TakeAutomated analysisunknown

Security readout for executives and security teams

Plain-English summary

This Linux kernel issue affects the rtl8150 USB Ethernet driver. A malformed or unexpected USB endpoint configuration could trigger a kernel warning when the driver submits USB requests. The source describes a mitigation through basic endpoint checking, but does not provide CVSS, impact severity, or evidence of real-world exploitation.

Executive priority

Treat this as routine kernel hygiene unless your environment permits untrusted USB access at scale. Patch through normal kernel update channels, with higher priority for kiosks, labs, desktops, and virtualized environments exposing USB devices.

Technical view

The flaw is in drivers/net/usb/rtl8150.c. Syzkaller found the driver could submit a URB using an endpoint type that did not match expectations, triggering a usb_submit_urb warning. Stable kernel commits add basic bulk and interrupt endpoint validation. The change was reported as not tested on real hardware.

Likely exposure

Exposure is most relevant to Linux systems using the rtl8150 USB Ethernet driver, especially where untrusted physical or emulated USB devices can be attached. The supplied data does not prove remote network exposure or broad exploitability.

Exploitation context

The CVE is not listed as KEV, and the source bundle contains no claim of active exploitation. The evidence comes from Syzkaller fuzzing, not a public exploit report. Practical exploitation requirements and impact remain unclear from the provided sources.

Researcher notes

Key uncertainty is impact beyond a kernel warning. The upstream note says the change was not tested on real hardware. Validation should focus on whether the fixed endpoint checks are present in your exact vendor kernel branch.

Mitigation direction

  • Apply vendor kernel updates containing the referenced stable fixes.
  • Prioritize systems allowing untrusted USB device attachment.
  • Check Debian LTS advisories if running Debian-based kernels.
  • Disable or restrict unused USB Ethernet hardware where operationally practical.
  • Monitor vendor guidance for impact or severity updates.

Validation and detection

  • Inventory Linux kernel versions across affected systems.
  • Identify systems using or loading the rtl8150 driver.
  • Confirm kernel packages include the referenced stable backports.
  • Review vendor advisories for Debian or distribution-specific fixed versions.
  • Check logs for repeated usb_submit_urb endpoint warnings.
Prepared
Confidence
medium
Sources
12

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

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CVE-2025-21708 mapping review

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

0CVSS vectors
3Timeline events
1ADP providers
11Source links

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. CVE publishedCVE Program

    The CVE record was published.

  3. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CVECVE Program Container
Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinux1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2unaffected
LinuxLinux2.6.12, 0, 5.4.291, 5.10.235, 5.15.179, 6.1.129, 6.6.76, 6.12.13, 6.13.2, 6.14affected
Weakness

CWE details

No CWE listed

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