Memory disclosure via Graph TLV length underflow
Published May 11, 2021 · Updated Aug 3, 2024
Integer underflow in Microsoft Office products allows context-dependent attackers to disclose uninitialized process memory via a crafted file. The Graph component subtracts eight from a seven-byte TLV record length, underflowing the size calculation and bypassing a bounds check before a large read. Exploitation requires a user to open and interact with crafted content; the Preview Pane alone does not trigger the flaw, and the disclosed impact is memory exposure.
Summary
What happened
Integer underflow in Microsoft Office products allows context-dependent attackers to disclose uninitialized process memory via a crafted file. The Graph component subtracts eight from a seven-byte TLV record length, underflowing the size calculation and bypassing a bounds check before a large read. Exploitation requires a user to open and interact with crafted content; the Preview Pane alone does not trigger the flaw, and the disclosed impact is memory exposure.
The record
- CVE
- CVE-2021-31178
- Published
- May 11, 2021
- Updated
- Aug 3, 2024
- Vendor
- Microsoft
- Product
- Microsoft Office 2016
- Classifications
- CWE-191
- Attack vector
- local
- Privileges
- unauthenticated
Timeline
How it unfolded
- May 11, 2021CVE publishedPublication date reported by the CVE source.
- Aug 3, 2024Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=16.0.0 <16.0.5161.1000
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- Check Point Graph parser crash proof of conceptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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