Microsoft Word Memory Corruption
CVE-2014-1761 is a high-severity out-of-bounds write vulnerability in Office from Microsoft, with a CVSS 2.0 base score of 9.3 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected Office versions: 2011. The record does not name a fixed version, so check the vendor advisory. CISA added it to the Known Exploited Vulnerabilities catalogue on February 15, 2022, which means attacks have been observed in the wild.
Attackers are already exploiting this vulnerability, according to CISA.
What to do
- Check which version of Office you run against the affected versions below, and install the vendor's latest release.
- CISA's required action: Apply updates per vendor instructions.
- Read the advisory on technet.microsoft.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Microsoft | Office | 2011 | Not stated |
| Microsoft | Office Compatibility Pack | Not specified in the record | Not stated |
| Microsoft | Office Web Apps | 2010 | Not stated |
| Microsoft | Office Web Apps Server | 2013 | Not stated |
| Microsoft | Sharepoint Server | 2010; 2013 | Not stated |
| Microsoft | Word | 2003; 2007; 2010; 2013 | Not stated |
| Microsoft | Word Viewer | Not specified in the record | Not stated |
Version data comes from NVD's product matching. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Access vector
- NetworkCan be exploited remotely over a network.
- Access complexity
- MediumSome conditions must be met.
- Authentication
- NoneNo login is needed.
- Confidentiality
- CompleteAll data can be read.
- Integrity
- CompleteAny data can be modified.
- Availability
- CompleteThe system can be shut down completely.
Vector: AV:N/AC:M/Au:N/C:C/I:C/A:C. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.8 | High | CISA (ADP) |
| CVSS 2.0 | 9.3 | High | NVD |
Official description
Microsoft Word 2003 SP3, 2007 SP3, 2010 SP1 and SP2, 2013, and 2013 RT; Word Viewer; Office Compatibility Pack SP3; Office for Mac 2011; Word Automation Services on SharePoint Server 2010 SP1 and SP2 and 2013; Office Web Apps 2010 SP1 and SP2; and Office Web Apps Server 2013 allow remote attackers to execute arbitrary code or cause a denial of service (memory corruption) via crafted RTF data, as exploited in the wild in March 2014.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Out-of-bounds Write
The product writes data past the end, or before the beginning, of the intended buffer.
How developers prevent this class of flaw
- Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, many languages that perform their own memory management, such as Java and Perl, are not subject to buffer overflows. Other languages, such as Ada and C#, typically provide overflow protection, but the protection can be disabled by the programmer. Be wary that a language's interface to native code may still be subject to overflows, even if the language itself is theoretically safe.
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. Examples include the Safe C String Library (SafeStr) by Messier and Viega, and the Strsafe.h library from Microsoft. These libraries provide safer versions of overflow-prone string-handling functions.
- Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index checking. D3-SFCV (Stack Frame Canary Validation) from D3FEND discusses canary-based detection in detail.
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-2014-1761US Government Resource
Other vulnerabilities in Office
- 7.5 High severity
- 7.8 High severity
Microsoft Office Security Feature Bypass Exploited
Recent Out-of-bounds Write vulnerabilities
- 8.8 High severity
Microsoft Windows Out-of-Bounds Write Exploited
- 9.8 Critical severity
- 8.8 High severity
- 7.8 High severity
- 9.3 High severity
Microsoft Word Remote Code Execution Exploited
- 8.8 High severity
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