How should we interpret CVSS severity scores?

CVSS estimates technical severity, but it does not automatically equal business risk. Prioritize using context like internet exposure, asset criticality, known exploitation, 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.

Vulnerability Database

Q: What is a Vulnerability (CVE) and why does it matter?

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.

Q: What's the difference between a vulnerability, an exploit, and a zero-day?

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. Risk increases sharply when exploitation becomes reliable or widespread.

Q: Why do vulnerabilities keep reappearing in our environment?

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.

Q: How do we prioritize remediation without burning out the team?

Use a 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 so remediation is steady, not reactive.

Q: How can SynScan help reduce vulnerability risk over time?

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.

374,587

Total vulnerabilities in the database

CVE-2023-53583 — linux / linux_kernel

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

perf: RISC-V: Remove PERF_HES_STOPPED flag checking in riscv_pmu_start()

Since commit 096b52fd2bb4 ("perf: RISC-V: throttle perf events") the perf_sample_event_took() function was added to report time spent in overflow interrupts. If the interrupt takes too long, the perf framework will lower the sysctl_perf_event_sample_rate and max_samples_per_tick. When hwc->interrupts is larger than max_samples_per_tick, the hwc->interrupts will be set to MAX_INTERRUPTS, and events will be throttled within the __perf_event_account_interrupt() function.

However, the RISC-V PMU driver doesn't call riscv_pmu_stop() to update the PERF_HES_STOPPED flag after perf_event_overflow() in pmu_sbi_ovf_handler() function to avoid throttling. When the perf framework unthrottled the event in the timer interrupt handler, it triggers riscv_pmu_start() function and causes a WARN_ON_ONCE() warning, as shown below:

------------[ cut here ]------------ WARNING: CPU: 0 PID: 240 at drivers/perf/riscv_pmu.c:184 riscv_pmu_start+0x7c/0x8e Modules linked in: CPU: 0 PID: 240 Comm: ls Not tainted 6.4-rc4-g19d0788e9ef2 #1 Hardware name: SiFive (DT) epc : riscv_pmu_start+0x7c/0x8e ra : riscv_pmu_start+0x28/0x8e epc : ffffffff80aef864 ra : ffffffff80aef810 sp : ffff8f80004db6f0 gp : ffffffff81c83750 tp : ffffaf80069f9bc0 t0 : ffff8f80004db6c0 t1 : 0000000000000000 t2 : 000000000000001f s0 : ffff8f80004db720 s1 : ffffaf8008ca1068 a0 : 0000ffffffffffff a1 : 0000000000000000 a2 : 0000000000000001 a3 : 0000000000000870 a4 : 0000000000000000 a5 : 0000000000000000 a6 : 0000000000000840 a7 : 0000000000000030 s2 : 0000000000000000 s3 : ffffaf8005165800 s4 : ffffaf800424da00 s5 : ffffffffffffffff s6 : ffffffff81cc7590 s7 : 0000000000000000 s8 : 0000000000000006 s9 : 0000000000000001 s10: ffffaf807efbc340 s11: ffffaf807efbbf00 t3 : ffffaf8006a16028 t4 : 00000000dbfbb796 t5 : 0000000700000000 t6 : ffffaf8005269870 status: 0000000200000100 badaddr: 0000000000000000 cause: 0000000000000003 [<ffffffff80aef864>] riscv_pmu_start+0x7c/0x8e [<ffffffff80185b56>] perf_adjust_freq_unthr_context+0x15e/0x174 [<ffffffff80188642>] perf_event_task_tick+0x88/0x9c [<ffffffff800626a8>] scheduler_tick+0xfe/0x27c [<ffffffff800b5640>] update_process_times+0x9a/0xba [<ffffffff800c5bd4>] tick_sched_handle+0x32/0x66 [<ffffffff800c5e0c>] tick_sched_timer+0x64/0xb0 [<ffffffff800b5e50>] __hrtimer_run_queues+0x156/0x2f4 [<ffffffff800b6bdc>] hrtimer_interrupt+0xe2/0x1fe [<ffffffff80acc9e8>] riscv_timer_interrupt+0x38/0x42 [<ffffffff80090a16>] handle_percpu_devid_irq+0x90/0x1d2 [<ffffffff8008a9f4>] generic_handle_domain_irq+0x28/0x36

After referring other PMU drivers like Arm, Loongarch, Csky, and Mips, they don't call *_pmu_stop() to update with PERF_HES_STOPPED flag after perf_event_overflow() function nor do they add PERF_HES_STOPPED flag checking in *_pmu_start() which don't cause this warning.

Thus, it's recommended to remove this unnecessary check in riscv_pmu_start() function to prevent this warning.

Published: Oct 4, 2025
Updated: Feb 11, 2026
CVE: CVE-2023-53583
Severity: Medium
Exploit:
CISA KEV:

CVSS v3:

Severity: Medium
Score: 5.5
AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

No CWE or OWASP classifications available.

Affected Software
References

Software	From	Fixed in
linux / linux_kernel	6.1	6.1.40
linux / linux_kernel	6.2	6.4.5
linux / linux_kernel	6.5-rc1	6.5-rc1.x

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Frequently Asked Questions

What is a Vulnerability (CVE) and why does it matter?

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.