In the Linux kernel, the following vulnerability has been resolved:
usb: gadget: ncm: Fix handling of zero block length packets
While connecting to a Linux host with CDC_NCM_NTB_DEF_SIZE_TX set to 65536, it has been observed that we receive short packets, which come at interval of 5-10 seconds sometimes and have block length zero but still contain 1-2 valid datagrams present.
According to the NCM spec:
"If wBlockLength = 0x0000, the block is terminated by a short packet. In this case, the USB transfer must still be shorter than dwNtbInMaxSize or dwNtbOutMaxSize. If exactly dwNtbInMaxSize or dwNtbOutMaxSize bytes are sent, and the size is a multiple of wMaxPacketSize for the given pipe, then no ZLP shall be sent.
wBlockLength= 0x0000 must be used with extreme care, because of the possibility that the host and device may get out of sync, and because of test issues.
wBlockLength = 0x0000 allows the sender to reduce latency by starting to send a very large NTB, and then shortening it when the sender discovers that there’s not sufficient data to justify sending a large NTB"
However, there is a potential issue with the current implementation, as it checks for the occurrence of multiple NTBs in a single giveback by verifying if the leftover bytes to be processed is zero or not. If the block length reads zero, we would process the same NTB infintely because the leftover bytes is never zero and it leads to a crash. Fix this by bailing out if block length reads zero.
| Software | From | Fixed in |
|---|---|---|
| linux / linux_kernel | 4.14.328 | 4.15 |
| linux / linux_kernel | 4.19.297 | 4.19.312 |
| linux / linux_kernel | 5.4.259 | 5.4.274 |
| linux / linux_kernel | 5.10.199 | 5.10.215 |
| linux / linux_kernel | 5.15.136 | 5.15.154 |
| linux / linux_kernel | 6.1.59 | 6.1.84 |
| linux / linux_kernel | 6.5.8 | 6.6 |
| linux / linux_kernel | 6.6.1 | 6.6.24 |
| linux / linux_kernel | 6.7 | 6.7.12 |
| linux / linux_kernel | 6.6 | 6.6.x |
| linux / linux_kernel | 6.6-rc6 | 6.6-rc6.x |
| linux / linux_kernel | 6.6-rc7 | 6.6-rc7.x |
| linux / linux_kernel | 6.8-rc1 | 6.8-rc1.x |
| linux / linux_kernel | 6.8-rc2 | 6.8-rc2.x |
| linux / linux_kernel | 6.8-rc3 | 6.8-rc3.x |
| linux / linux_kernel | 6.8-rc4 | 6.8-rc4.x |
| linux / linux_kernel | 6.8-rc5 | 6.8-rc5.x |
| linux / linux_kernel | 6.8-rc6 | 6.8-rc6.x |
| linux / linux_kernel | 6.8-rc7 | 6.8-rc7.x |
| debian / debian_linux | 10.0 | 10.0.x |
A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.
CVSS (Common Vulnerability Scoring System) estimates technical severity, but it doesn't automatically equal business risk. Prioritize using context like internet exposure, affected asset criticality, known exploitation (proof-of-concept or in-the-wild), and whether compensating controls exist. A "Medium" CVSS on an exposed, production system can be more urgent than a "Critical" on an isolated, non-production host.
A vulnerability is the underlying weakness. An exploit is the method or code used to take advantage of it. A zero-day is a vulnerability that is unknown to the vendor or has no publicly available fix when attackers begin using it. In practice, risk increases sharply when exploitation becomes reliable or widespread.
Recurring findings usually come from incomplete Asset Discovery, inconsistent patch management, inherited images, and configuration drift. In modern environments, you also need to watch the software supply chain: dependencies, containers, build pipelines, and third-party services can reintroduce the same weakness even after you patch a single host. Unknown or unmanaged assets (often called Shadow IT) are a common reason the same issues resurface.
Use a simple, repeatable triage model: focus first on externally exposed assets, high-value systems (identity, VPN, email, production), vulnerabilities with known exploits, and issues that enable remote code execution or privilege escalation. Then enforce patch SLAs and track progress using consistent metrics so remediation is steady, not reactive.
SynScan combines attack surface monitoring and continuous security auditing to keep your inventory current, flag high-impact vulnerabilities early, and help you turn raw findings into a practical remediation plan.