What is CVE-2021-28550?

CVE-2021-28550 is a high-severity vulnerability in Adobe Acrobat, classified under Use After Free. CVSS score: 8.8/10. Published 2021-09-02.

How severe is CVE-2021-28550?

High severity. CVSS v3 base score is 8.8 out of 10.

Is CVE-2021-28550 known to be exploited?

Yes. CVE-2021-28550 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2021-11-03), indicating it is being actively exploited. 14 public proof-of-concept repositories are indexed.

Use After Free in Adobe Acrobat

CVE-2021-28550

Acrobat Reader DC versions versions 2021.001.20150 (and earlier), 2020.001.30020 (and earlier) and 2017.011.30194 (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.

Vulnerability class: Use-After-Free

EPSS: 0.520 (98.9th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.

Affected products

Adobe Acrobat
Adobe Acrobat_dc
Adobe Acrobat Reader — versions unspecified
Adobe Acrobat_reader
Adobe Acrobat_reader_dc
Apple Macos
Microsoft Windows

Weakness classification (CWE)

CWE-416 — Use After Free

CISA KEV (Known Exploited Vulnerabilities)

This CVE is on the CISA KEV catalog, added on 2021-11-03. CISA KEV inclusion means CISA has confirmed in-the-wild exploitation; US federal agencies are required to remediate within a published due date.

BOD 22-01 due date: 2021-11-17.

Required action: Apply updates per vendor instructions.

Public proof-of-concept exploits

References

psirt@adobe.com (Release Notes, Vendor Advisory)
134c704f-9b21-4f2e-91b3-4a467353bcc0 (Third Party Advisory, US Government Resource)

Frequently asked questions

What is CVE-2021-28550?: CVE-2021-28550 is a high-severity vulnerability in Adobe Acrobat, classified under Use After Free. CVSS score: 8.8/10. Published 2021-09-02.
How severe is CVE-2021-28550?: High severity. CVSS v3 base score is 8.8 out of 10.
Is CVE-2021-28550 known to be exploited?: Yes. CVE-2021-28550 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2021-11-03), indicating it is being actively exploited. 14 public proof-of-concept repositories are indexed.