Adobe Acrobat Reader DC NTLMv2 SSO Information Disclosure via LoadFile
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- Required
- Attack complexity
- Low
- Impact type
- Information disclosure
- Confidentiality · integrity · availability
- High · None · None
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-200.
Summary
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.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Adobe | Acrobat Reader | up to 2020.004.30006; up to 2017.011.30199; up to 2021.005.20060; up to None | — | No fix listed | CNA |
- Acrobat Reader VendorAdobe Affected up to 2020.004.30006; up to 2017.011.30199; up to 2021.005.20060; up to None Fixed in — No fix listed CNA
CPE configurations NVD · 10
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:adobe:acrobat:*:*:*:*:classic:*:*:* | 17.011.30059 – 17.011.30199 | Vulnerable | Adobe |
| cpe:2.3:a:adobe:acrobat_reader:*:*:*:*:classic:*:*:* | 17.011.30059 – 17.011.30199 | Vulnerable | Adobe |
| cpe:2.3:o:apple:macos:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Apple |
| cpe:2.3:o:microsoft:windows:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Microsoft |
| cpe:2.3:a:adobe:acrobat:*:*:*:*:classic:*:*:* | 20.001.30005 – 20.004.30006 | Vulnerable | Adobe |
| cpe:2.3:a:adobe:acrobat_reader:*:*:*:*:classic:*:*:* | 20.001.30005 – 20.004.30006 | Vulnerable | Adobe |
| cpe:2.3:a:adobe:acrobat_dc:*:*:*:*:continuous:*:*:* | 15.008.20082 – 21.005.20058 | Vulnerable | Adobe |
| cpe:2.3:a:adobe:acrobat_reader_dc:*:*:*:*:continuous:*:*:* | 15.008.20082 – 21.005.20058 | Vulnerable | Adobe |
| cpe:2.3:a:adobe:acrobat_dc:*:*:*:*:continuous:*:*:* | 15.008.20082 – 21.005.20060 | Vulnerable | Adobe |
| cpe:2.3:a:adobe:acrobat_reader_dc:*:*:*:*:continuous:*:*:* | 15.008.20082 – 21.005.20060 | Vulnerable | Adobe |
- cpe:2.3:a:adobe:acrobat:*:*:*:*:classic:*:*:* Versions 17.011.30059 – 17.011.30199 Vulnerable ·Adobe
- cpe:2.3:a:adobe:acrobat_reader:*:*:*:*:classic:*:*:* Versions 17.011.30059 – 17.011.30199 Vulnerable ·Adobe
- cpe:2.3:o:apple:macos:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Apple
- cpe:2.3:o:microsoft:windows:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Microsoft
- cpe:2.3:a:adobe:acrobat:*:*:*:*:classic:*:*:* Versions 20.001.30005 – 20.004.30006 Vulnerable ·Adobe
- cpe:2.3:a:adobe:acrobat_reader:*:*:*:*:classic:*:*:* Versions 20.001.30005 – 20.004.30006 Vulnerable ·Adobe
- cpe:2.3:a:adobe:acrobat_dc:*:*:*:*:continuous:*:*:* Versions 15.008.20082 – 21.005.20058 Vulnerable ·Adobe
- cpe:2.3:a:adobe:acrobat_reader_dc:*:*:*:*:continuous:*:*:* Versions 15.008.20082 – 21.005.20058 Vulnerable ·Adobe
- cpe:2.3:a:adobe:acrobat_dc:*:*:*:*:continuous:*:*:* Versions 15.008.20082 – 21.005.20060 Vulnerable ·Adobe
- cpe:2.3:a:adobe:acrobat_reader_dc:*:*:*:*:continuous:*:*:* Versions 15.008.20082 – 21.005.20060 Vulnerable ·Adobe
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2021-39856
- 2026-10-03 Alias added: GHSA-p74c-qp2j-549x
References
More Adobe Acrobat vulnerabilities
- TI-2014-00524 Adobe Reader and Acrobat 10.x before 10.1.11 and 11.x before 11.0.08 on Windows allow… KEVCVSS 3.1CRITICAL 9.8
- TI-2013-02915 Adobe Reader and Acrobat 9.x before 9.5.5, 10.x before 10.1.7, and 11.x before 11.0.03… KEVCVSS 3.1CRITICAL 9.8
- TI-2013-02389 Integer overflow in Adobe Reader and Acrobat 9.x before 9.5.5, 10.x before 10.1.7, and… KEVCVSS 3.1CRITICAL 9.8
- TI-2011-02156 Unspecified vulnerability in the U3D component in Adobe Reader and Acrobat 10.1.1 and… KEVCVSS 3.1CRITICAL 9.8
- TI-2021-09626 Adobe Acrobat Reader use after free vulnerability could lead to arbitrary code execution KEVCVSS 3.1HIGH 8.8
- TI-2021-04123 Acrobat Reader DC Heap-based Buffer Overflow Vulnerability Could Lead To Arbitrary Code Execution KEVCVSS 3.1HIGH 8.8
Sources
- CVE-2021-39856 · CVE Program
- CVE-2021-39856 · NVD
- FIRST EPSS
- GHSA-p74c-qp2j-549x · GitHub Advisory Database · CC BY 4.0
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