How severe is CVE-2023-21700?

CVE-2023-21700 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2023-21700 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (74th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2023-21700?

CVE-2023-21700 primarily affects Microsoft Windows 10. In total, 15 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2023-21700?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2023-21700 published?

CVE-2023-21700 was published on 2023-02-14 and last updated on 2026-06-17.

CVE-2023-21700

CVE-2023-21700 is a high-severity vulnerability in Microsoft Windows 10 with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-476.

Key facts

Severity: High (CVSS 3.x base score 7.5)
EPSS exploit prediction: 2% (74th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-476
Affected product: Microsoft Windows 10
Published: 2023-02-14
Last modified: 2026-06-17

Description

Windows iSCSI Discovery Service Denial of Service Vulnerability

Frequently asked questions

What is CVE-2023-21700?: Windows iSCSI Discovery Service Denial of Service Vulnerability
How severe is CVE-2023-21700?: CVE-2023-21700 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2023-21700 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (74th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-21700?: CVE-2023-21700 primarily affects Microsoft Windows 10. In total, 15 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2023-21700?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2023-21700 published?: CVE-2023-21700 was published on 2023-02-14 and last updated on 2026-06-17.

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-21700

Affected products (15)

cpe:2.3:o:microsoft:windows_10:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_10_1607:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_10_1809:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_10_20h2:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_10_21h2:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_10_22h2:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_11_21h2:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_11_22h2:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2008:-:sp2:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2008:r2:sp1:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_server_2012:-:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2012:r2:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2016:-:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2019:-:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2022:-:*:*:*:*:*:*:*

More vulnerabilities in Microsoft Windows 10

CVE-2020-1467 — Critical (CVSS 10.0): An elevation of privilege vulnerability exists when Windows improperly handles hard links. An attacker who successfully…
CVE-2021-26424 — Critical (CVSS 9.9): Windows TCP/IP Remote Code Execution Vulnerability
CVE-2021-28476 — Critical (CVSS 9.9): Windows Hyper-V Remote Code Execution Vulnerability
CVE-2021-26867 — Critical (CVSS 9.9): Windows Hyper-V Remote Code Execution Vulnerability
CVE-2020-1112 — Critical (CVSS 9.9): An elevation of privilege vulnerability exists when the Windows Background Intelligent Transfer Service (BITS) IIS…
CVE-2019-1384 — Critical (CVSS 9.9): A security feature bypass vulnerability exists where a NETLOGON message is able to obtain the session key and sign…

All CVEs affecting Microsoft Windows 10 →

Other CWE-476 (NULL Pointer Dereference) vulnerabilities

CVE-2022-36648 — Critical (CVSS 10.0): The hardware emulation in the of_dpa_cmd_add_l2_flood of rocker device model in QEMU, as used in 7.0.0 and earlier,…
CVE-2020-14500 — Critical (CVSS 10.0): Secomea GateManager all versions prior to 9.2c, An attacker can send a negative value and overwrite arbitrary data.
CVE-2010-2495 — Critical (CVSS 10.0): The pppol2tp_xmit function in drivers/net/pppol2tp.c in the L2TP implementation in the Linux kernel before 2.6.34 does…
CVE-2026-46195 — Critical (CVSS 9.8): In the Linux kernel, the following vulnerability has been resolved: smb: client: validate dacloffset before building…
CVE-2026-31657 — Critical (CVSS 9.8): In the Linux kernel, the following vulnerability has been resolved: batman-adv: hold claim backbone gateways by…
CVE-2026-31436 — Critical (CVSS 9.8): In the Linux kernel, the following vulnerability has been resolved: dmaengine: idxd: fix possible wrong descriptor…

Browse all CWE-476 (NULL Pointer Dereference) vulnerabilities →