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Fencer Intel
high 8.8

CVE-2021-21028 json

Acrobat Reader DC Use-After-Free Vulnerability Could Lead To Arbitrary Code Execution

published 5y ago modified 4mo ago also CVE-2021-21043 , GHSA-7r83-w6r8-fh6w , GHSA-f92j-qf46-p6vm , EUVD-2021-0551

cvss
8.8
version 3.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
4.3%
EPSS 4.3% chance of exploitation in 30 days, percentile 91%
public exploits
0
none known

Summary

Acrobat Reader DC versions versions 2020.013.20074 (and earlier), 2020.001.30018 (and earlier) and 2017.011.30188 (and earlier) are affected by a Use After Free vulnerability. An unauthenticated attacker could leverage this vulnerability to achieve arbitrary code execution in the context of the current user. Exploitation of this issue requires user interaction in that a victim must open a malicious file.

Patch / fix

  • maven com.adobe.acs:acs-aem-commons 4.10.0

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Exploit prediction

4.30% chance of exploitation in the next 30 days, higher than 91% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
CNA 3.0 8.8 CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
NVD 3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
NVD 2.0 6.8 AV:N/AC:M/Au:N/C:P/I:P/A:P
GitHub 3.1 6.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Affected packages

ecosystem package affected fixed in
maven com.adobe.acs:acs-aem-commons
<4.10.0
4.10.0

Affected products

  • Adobe Acrobat Reader

Classification

Weakness
  • CWE-416 Use After Free
  • CWE-79 Improper Neutralization of Input During Web Page Generation
  • CWE-787 Out-of-bounds Write

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.