CVE-2021-39856: Adobe Acrobat Reader DC NTLMv2 SSO Information Disclosure via LoadFile
First published: Wed Sep 29 2021(Updated: )
Acrobat Reader DC ActiveX Control versions 2021.005.20060 (and earlier), 2020.004.30006 (and earlier) and 2017.011.30199 (and earlier) are affected by an Information Disclosure vulnerability. An unauthenticated attacker could leverage this vulnerability to obtain NTLMv2 credentials. Exploitation of this issue requires user interaction in that a victim must visit an attacker controlled web page.
Credit: psirt@adobe.com
| Affected Software | Affected Version | How to fix |
|---|---|---|
| Adobe Acrobat Reader | >=17.011.30059<=17.011.30199 | |
| Adobe Acrobat Reader | >=17.011.30059<=17.011.30199 | |
| Apple iOS and macOS | ||
| Microsoft Windows | ||
| Adobe Acrobat Reader | >=20.001.30005<=20.004.30006 | |
| Adobe Acrobat Reader | >=20.001.30005<=20.004.30006 | |
| Adobe Acrobat | >=15.008.20082<=21.005.20058 | |
| Adobe Acrobat Reader | >=15.008.20082<=21.005.20058 | |
| Adobe Acrobat | >=15.008.20082<=21.005.20060 | |
| Adobe Acrobat Reader | >=15.008.20082<=21.005.20060 |
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Frequently Asked Questions
What is the severity of CVE-2021-39856?
CVE-2021-39856 is classified as an Information Disclosure vulnerability that could lead to the exposure of NTLMv2 credentials.
How do I fix CVE-2021-39856?
The fix for CVE-2021-39856 is to update Adobe Acrobat Reader DC to a version that is not affected, specifically versions newer than 2021.005.20060.
What versions of Adobe Acrobat Reader are affected by CVE-2021-39856?
CVE-2021-39856 affects Adobe Acrobat Reader DC versions 2021.005.20060 and earlier, 2020.004.30006 and earlier, and 2017.011.30199 and earlier.
Can CVE-2021-39856 be exploited remotely?
Yes, CVE-2021-39856 can be exploited by an unauthenticated attacker to gain sensitive information.
What systems are at risk with CVE-2021-39856?
CVE-2021-39856 affects installations of Adobe Acrobat and Acrobat Reader on various operating systems, particularly if not updated to the latest versions.
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- agent/description
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- agent/severity
- collector/mitre-cve
- source/MITRE
- agent/last-modified-date
- agent/first-publish-date
- agent/event
- agent/source
- agent/softwarecombine
- agent/tags
- collector/nvd-index
- agent/software-canonical-lookup-request
- vendor/adobe
- canonical/adobe acrobat reader
- version/adobe acrobat reader/17.011.30059
- version/adobe acrobat reader/17.011.30199
- vendor/apple
- canonical/apple ios and macos
- vendor/microsoft
- canonical/microsoft windows
- version/adobe acrobat reader/20.001.30005
- version/adobe acrobat reader/20.004.30006
- canonical/adobe acrobat
- version/adobe acrobat/15.008.20082
- version/adobe acrobat/21.005.20058
- version/adobe acrobat reader/15.008.20082
- version/adobe acrobat reader/21.005.20058
- version/adobe acrobat/21.005.20060
- version/adobe acrobat reader/21.005.20060