CVE-2024-43521: Microsoft Windows Server 2012 · Incorrect Check of Function Return Value
Affects Microsoft Windows Server 2012Source CVE Database V5
Not known to be exploited · CVSS 7.5 High : upgrade to 6.2.9200.25118 soon.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 2.4% chance of exploitation in 30 days – higher than 84% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- CISA SSVC
- Exploitation
- No evidence of active exploitation and no public proof of concept
- Automatable
- Attackers can reliably automate steps 1–4 of the kill chain
- Technical impact
- Limited control over the software or limited information exposure
CISA SSVC assessment, 2024-10-09.
- Patch
- Available – fixed in 6.2.9200.25118, 6.3.9600.22221, 10.0.14393.7428 +3
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:CExploitation evidence
Disclosed: evidence found.
CVE published 8 Oct 2024
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| MicrosoftWindows Server 2012 | Affected
| Fixed in
|
| MicrosoftWindows Server 2012 (Server Core installation) | Affected
| Fixed in
|
| MicrosoftWindows Server 2012 R2 | Affected
| Fixed in
|
| MicrosoftWindows Server 2012 R2 (Server Core installation) | Affected
| Fixed in
|
| MicrosoftWindows Server 2016 | Affected
| Fixed in
|
| MicrosoftWindows Server 2016 (Server Core installation) | Affected
| Fixed in
|
AI-suggested
Microsoft has released official patches that address this vulnerability in the specified fixed versions. Administrators should apply these updates promptly to remediate the issue. Since an official fix is available, no additional mitigation steps are required beyond patching.
Description
CVE-2024-43521 is a high-severity vulnerability in Microsoft Windows Server 2012 related to an incorrect check of a function return value in the Windows Hyper-V component. This flaw can lead to a denial of service condition. The vulnerability affects multiple Windows Server 2012 and related versions prior to specific fixed releases. An official fix is available from Microsoft.