CVE-2015-1701
CVE-2015-1701 is a security flaw in Microsoft Win32k, a part of Windows, Microsoft’s operating system. Someone who already has a way in can use Microsoft Win32k to run their own code. The US Cybersecurity and Infrastructure Security Agency (CISA) added it to its catalog of flaws known to be used in attacks on 3 Mar 2022, and says ransomware gangs have used it.[1]
Microsoft Win32k is in things households have, such as phones, computers, browsers and everyday apps, so the fix matters at home as much as at work. Microsoft has published a fix or advice.
Description
CISA calls it a privilege escalation in Microsoft Win32k. In its words: “An unspecified vulnerability exists in the Win32k.sys kernel-mode driver in Microsoft Windows Server that allows a local attacker to execute arbitrary code with elevated privileges.”[1]
The CVE record adds: “Win32k.sys in the kernel-mode drivers in Microsoft Windows Server 2003 SP2, Vista SP2, and Server 2008 SP2 allows local users to gain privileges via a crafted application, as exploited in the wild in April 2015, aka "Win32k Elevation of Privilege Vulnerability."”[2]
The underlying weakness is permissions and access control (CWE-264), in MITRE’s list of common software weaknesses.
It scores 7.8 out of 10 on the Common Vulnerability Scoring System, which rates it high, scored by NVD using CVSS 3.1.[2]
Affected versions
NVD’s record doesn’t list version ranges for it; Microsoft’s advisory has them[3]. CISA names the product as Microsoft Win32k.
Every device with Microsoft Win32k needs the update.
Exploitation
CISA added it to its catalog of known exploited vulnerabilities on 3 Mar 2022, 2,508 days after it was made public. CISA lists a flaw only when it has reliable evidence of it being exploited, and gave US federal agencies until 24 Mar 2022 to fix it.[1] CISA says ransomware gangs have used it.
FIRST’s Exploit Prediction Scoring System, which estimates how likely a flaw is to be used in attacks in the next 30 days from what it sees across the internet, puts it at 56%. That’s in the top 1% of the flaws it scores.[4]
CISA assesses it as not automatable: each attack takes some work.
CISA doesn’t say who was attacked, or how.
Fix
Microsoft has published a fix or advice.[3] CISA’s required action: “Apply updates per vendor instructions.”[1]
- Update Microsoft Win32k now.On Windows: Settings, Windows Update, Check for updates, then restart. Office updates come the same way, or from any Office app: File, Account, Update Options. Then turn on automatic updates, so the next fix arrives on its own.
- If there’s no update, stop using it.CISA’s advice when a flaw being used in attacks has no fix is to stop using the product until it does.
Timeline
| Date | Event |
|---|---|
| The flaw is made public in the National Vulnerability Database, with a severity score of 7.8.[2] | |
| CISA adds it to its catalog of flaws known to be used in attacks, noting that ransomware gangs have used it.[1] | |
| CISA’s deadline for US government agencies to fix it.[1] | |
| FIRST puts the odds of it being used in attacks in the next 30 days at 56%.[4] |
See also
Other Microsoft Win32k flaws
- CVE-2016-0165: privilege escalation ·
- CVE-2023-29336: privilege escalation ·
- CVE-2015-2360: privilege escalation ·
- CVE-2018-8589: privilege escalation ·
- CVE-2014-4113: privilege escalation ·
- CVE-2021-41357: privilege escalation ·
Other Microsoft flaws
- CVE-2026-96951, Microsoft Windows: command injection ·
- CVE-2026-65660, Microsoft SharePoint: code injection ·
- CVE-2026-85880, Microsoft Windows: heap-based buffer overflow ·
- CVE-2026-81963, Microsoft Windows: link following ·
- CVE-2019-1068, Microsoft SQL Server: remote code execution ·
Other permissions and access control flaws
- CVE-2015-3246, Red Hat Libuser: race condition ·
- CVE-2013-0643, Adobe Flash Player: incorrect default permissions ·
- CVE-2015-0310, Adobe Flash Player: ASLR bypass ·
- CVE-2013-3993, IBM InfoSphere BigInsights: invalid input ·
- CVE-2013-0422, Oracle Java Runtime Environment (JRE): JRE remote code execution ·
Added the same day
- CVE-2022-20708, Cisco Small Business RV160, RV260, RV340, and RV345 Series Routers: small business RV series routers stack-based buffer overflow ·
- CVE-2022-20703, Cisco Small Business RV160, RV260, RV340, and RV345 Series Routers: small business RV series routers stack-based buffer overflow ·
- CVE-2022-20701, Cisco Small Business RV160, RV260, RV340, and RV345 Series Routers: small business RV series routers stack-based buffer overflow ·
- CVE-2022-20700, Cisco Small Business RV160, RV260, RV340, and RV345 Series Routers: small business RV series routers stack-based buffer overflow ·
- CVE-2022-20699, Cisco Small Business RV160, RV260, RV340, and RV345 Series Routers: small business RV series routers stack-based buffer overflow ·
Every Microsoft flaw on CISA’s list · Everything added in March 2022
References
- ^ Cybersecurity and Infrastructure Security Agency. “Microsoft Win32k Privilege Escalation Vulnerability”. Known Exploited Vulnerabilities Catalog, added 3 Mar 2022.
- ^ National Institute of Standards and Technology. “CVE-2015-1701 Detail”. National Vulnerability Database, published 21 Apr 2015.
- ^ Microsoft. Advisories and fixes: docs.microsoft.com.
- ^ FIRST. “Exploit Prediction Scoring System”. EPSS 0.559, percentile 99.0, 31 Oct 2026.
- CVE Program. “CVE-2015-1701”. The official CVE record.
This article is built from CISA’s catalog (version 2026.10.30), NVD’s record and FIRST’s scores, kept in HARD’s database and checked every morning. The plain English is HARD’s.