CVE-2021-44739Network attack vector

NTLMv2 credential disclosure via ActiveX control

Published Jan 14, 2022 · Updated Sep 16, 2024

Information disclosure in Adobe Acrobat Reader DC ActiveX Control before 21.007.20099 allows unauthenticated attackers to obtain NTLMv2 credentials. The AxAcroPDF ActiveX component initiates an NTLM authentication request when handling attacker-controlled Office content or a web page, exposing the resulting challenge-response material. Exploitation requires a victim to open a malicious Office file or visit an attacker-controlled page; the documented impact is credential disclosure rather than code execution or service interruption.

CVSS severity4.3
Medium
EPSS probability2.07%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information disclosure in Adobe Acrobat Reader DC ActiveX Control before 21.007.20099 allows unauthenticated attackers to obtain NTLMv2 credentials. The AxAcroPDF ActiveX component initiates an NTLM authentication request when handling attacker-controlled Office content or a web page, exposing the resulting challenge-response material. Exploitation requires a victim to open a malicious Office file or visit an attacker-controlled page; the documented impact is credential disclosure rather than code execution or service interruption.

The record

CVE
CVE-2021-44739
Published
Jan 14, 2022
Updated
Sep 16, 2024
Vendor
Adobe
Product
Adobe Acrobat Reader
Classifications
CWE-200, T1189
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 14, 2022CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 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.

  1. Affected versionversion=unspecified <=17.011.30204
  2. Affected versionversion=unspecified <=20.004.30017
  3. Affected versionversion=unspecified <=21.007.20099
  4. Affected versionversion=unspecified <=None

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Adobe · Adobe Acrobat Readerversion=unspecified <=17.011.30204; version=unspecified <=20.004.30017; version=unspecified <=21.007.20099; version=unspecified <=None

Published CVSS scores

3.1Adobe Systems IncorporatedCVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:N
4.3NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N
4.3NIST NVDAV:N/AC:M/Au:N/C:P/I:N/A:N

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-200Exposure of Sensitive Information to an Unauthorized Actor
T1189Drive-by Compromise

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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