CVE-2021-21028

mediumpriority · track · 36EPSS 0.041 · 91 %ileEURUUS

grimoire priorityP3 · Track

Exploitable?

—

no known exploitation

Likely / severe?

4.12% (91st) EPSS

CVSS 6.8 · medium

Is it mine?

17 products

Check your exposure

Who says so?

5 sources

cnnvd · enisa_euvd · fstec_bdu · osv

EPSS · scored 2026-10-28

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.

cvss

Technical severity, 0–10. One row per scoring source.

8.8

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 6.1–8.8

v2.06.8mediumAV:N/AC:M/Au:N/C:P/I:P/A:Pprimary · NVD / NIST USexploitability 8.6 · impact 6.4

v3.18.8highCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:Hprimary · NVD / NIST USexploitability 2.8 · impact 5.9

v3.08.8highCVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:Hsecondary · ENISA EU

v3.08.8highCVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:Hsecondary · psirt@adobe.comexploitability 2.8 · impact 5.9

v3.18.1highCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:Usecondary · CVSS-BT (t0sche)

v3.16.1mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:Nsecondary · OSV

v3.18.8highAV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:Hsecondary · FSTEC (BDU) RU

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-416USCWE-416USCWE-416USCWE-787USCWE-79US

affected products (17)

Products and version ranges known to be affected.

Adobe Acrobat Reader≤ unspecified ≤2017.011.30188enisa_euvdEU
Adobe Acrobat Reader≤ unspecified ≤2020.001.30018enisa_euvdEU
Adobe Acrobat Reader≤ unspecified ≤Noneenisa_euvdEU
Adobe Acrobat Reader≤ unspecified ≤2020.013.20074enisa_euvdEU
Adobe Systems Inc. Adobe Acrobat 2017≤ 2017.011.30190 Classic 2017fstec_bduRU
Adobe Systems Inc. Adobe Acrobat 2020≤ 2020.001.30020 Classic 2020fstec_bduRU
Adobe Systems Inc. Adobe Acrobat Document Cloud≤ 2021.001.20135 Continuousfstec_bduRU
Adobe Systems Inc. Adobe Acrobat Reader 2017≤ 2017.011.30190 Classic 2017fstec_bduRU
Adobe Systems Inc. Adobe Acrobat Reader 2020≤ 2020.001.30020 Classic 2020fstec_bduRU
Adobe Systems Inc. Adobe Acrobat Reader Document Cloud≤ 2021.001.20135 Continuousfstec_bduRU
adobe acrobat17.0 → 17.011.30188nvdUScpe:2.3:a:adobe:acrobat:*:*:*:*:*:*:*:*
adobe acrobat20.0 → 20.001.30018nvdUScpe:2.3:a:adobe:acrobat:*:*:*:*:*:*:*:*
adobe acrobat dc≤ 20.013.20074nvdUScpe:2.3:a:adobe:acrobat_dc:*:*:*:*:*:*:*:*
adobe acrobat reader17.0 → 17.011.30188nvdUScpe:2.3:a:adobe:acrobat_reader:*:*:*:*:*:*:*:*
adobe acrobat reader20.0 → 20.001.300183nvdUScpe:2.3:a:adobe:acrobat_reader:*:*:*:*:*:*:*:*
adobe acrobat reader dc≤ 20.013.20074nvdUScpe:2.3:a:adobe:acrobat_reader_dc:*:*:*:*:*:*:*:*
Maven com.adobe.acs:acs-aem-commons< 4.10.0osvUSpkg:maven/com.adobe.acs/acs-aem-commons

advisories (3)

Vendor and ecosystem advisories describing this.

GHSA-7r83-w6r8-fh6wReflected Cross-site Scripting (XSS) in ACS Commons2021-05-13ghsa · osvUS
ACS Commons version 4.9.2 (and earlier) suffers from a Reflected Cross-site Scripting (XSS) vulnerability in version-compare and page-compare due to invalid JCR characters that are not handled correctly. An attacker could potentially exploit this vulnerability to inject malicious JavaScript content into vulnerable form fields and execute it within the context of the victim's browser. Exploitation of this issue requires user interaction in order to be successful.
GHSA-f92j-qf46-p6vmReflected Cross-site Scripting in ACS Commons2021-02-02ghsa · osvUS
### Impact ACS Commons version 4.9.2 (and earlier) suffers from a Reflected Cross-site Scripting (XSS) vulnerability in version-compare and page-compare due to invalid JCR characters that are not handled correctly. An attacker could potentially exploit this vulnerability to inject malicious JavaScript content into vulnerable form fields and execute it within the context of the victim's browser. Exploitation of this issue requires user interaction in order to be successful. ### Patches This issue has been resolved in v4.10.0 ### Workarounds No workaround exist. ### References N/A ### For more information If you have any questions or comments about this advisory open an issue in acs-aem-commons. ### Credit This issue was discovered and reported by Christopher Whipp (Christopher.Whipp@servicesaustralia.gov.au).
CVE-2021-210432021-02-02vendor · osvUS
ACS Commons version 4.9.2 (and earlier) suffers from a Reflected Cross-site Scripting (XSS) vulnerability in version-compare and page-compare due to invalid JCR characters that are not handled correctly. An attacker could potentially exploit this vulnerability to inject malicious JavaScript content into vulnerable form fields and execute it within the context of the victim's browser. Exploitation of this issue requires user interaction in order to be successful.

also known as (6)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd fstec_bdu osv nvd NVD CVE.org MITRE

published 2021-02-11modified 2026-06-17

references (7)

External citations — patches, advisories, analysis.

scry

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