CVE-2021-28550 — Adobe Acrobat and Reader Use-After-Free Vulnerability

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

01What is this vulnerability?

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…

02Affected products

Vendor	Product	Versions
Adobe	Acrobat Reader	unspecified, unspecified, unspecified, unspecified

03Active exploitation status

Yes — actively exploited. Added to the CISA KEV catalog on 2021-11-03. Ransomware use: Unknown.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Open the Sigma generator with a pre-filled prompt for this CVE to draft a starting detection in your stack of choice:

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07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2021-09-02T16:07:20.687Z
• Last modified: 2025-10-21T23:25:35.586Z
• Added to CISA KEV: 2021-11-03
• BOD 22-01 due: 2021-11-17

09References

• helpx.adobe.com — https://helpx.adobe.com/security/products/acrobat/apsb21-29.html