Microsoft Office Remote Code Execution
CVE-2021-27059 is a medium-severity vulnerability in Microsoft Office 2010 Service Pack 2 from Microsoft, with a CVSS 3.1 base score of 6.5 out of 10. It can be exploited with local access to the system by an attacker with administrator privileges, but only if a user takes part, for example by opening a link or file. The record lists version 14.0.7266.5000 as the first without the flaw, so updating Microsoft Office 2010 Service Pack 2 to that release or later removes the exposure. CISA added it to the Known Exploited Vulnerabilities catalogue on November 3, 2021, which means attacks have been observed in the wild.
Attackers are already exploiting this vulnerability, according to CISA.
What to do
- Update Microsoft Office 2010 Service Pack 2 to 14.0.7266.5000 or a later version.
- Update Microsoft Office 2013 Service Pack 1 to publication or a later version.
- Update Microsoft Office 2016 to 16.0.5134.1000 or a later version.
- CISA's required action: Apply updates per vendor instructions.
- Read the advisory on msrc.microsoft.com for workarounds and exact fixed builds.
- Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Microsoft | Microsoft Office 2010 Service Pack 2 | 13.0.0.0 up to, but not including, 14.0.7266.5000 | 14.0.7266.5000 |
| Microsoft | Microsoft Office 2013 Service Pack 1 | 15.0.0 up to, but not including, publication | publication |
| Microsoft | Microsoft Office 2016 | 16.0.0 up to, but not including, 16.0.5134.1000 | 16.0.5134.1000 |
| Microsoft | Office | 2010; 2013 | Not stated |
| Microsoft | Office 2016 | Not specified in the record | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- HighAdministrator-level access is required first.
- User interaction
- RequiredA user must take an action such as opening a file or link.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:R/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.6 | High | CNA (microsoft.com) |
| CVSS 3.1 | 6.5 | Medium | NVD |
| CVSS 2.0 | 8.5 | High | NVD |
Official description
Microsoft Office Remote Code Execution Vulnerability
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
Timeline
- CVE record published.
- Added to CISA's Known Exploited Vulnerabilities catalogue.
- Deadline for US federal agencies to remediate, set by CISA.
- CISA published its SSVC assessment (exploitation: active, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Advisories
Third-party and government advisories
- cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-27059US Government Resource
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