What is CVE-2021-21017?

CVE-2021-21017 is a high-severity vulnerability in Adobe Acrobat Reader, classified under Heap-based Buffer Overflow. CVSS score: 8.8/10. Published 2021-02-11.

How severe is CVE-2021-21017?

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

Is CVE-2021-21017 known to be exploited?

Yes. CVE-2021-21017 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2021-11-03), indicating it is being actively exploited. 22 public proof-of-concept repositories are indexed.

Buffer overflow in Adobe Acrobat Reader

CVE-2021-21017

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 heap-based buffer overflow vulnerability. An unauthenticated attacker could leverage this vul…

Vulnerability class: Buffer Overflow

EPSS: 0.902 (99.6th 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 Reader — versions unspecified

Weakness classification (CWE)

CWE-122 — Heap-based Buffer Overflow

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

helpx.adobe.com/security/products/acrobat/apsb21-09.html (x_refsource_MISC)

Frequently asked questions

What is CVE-2021-21017?: CVE-2021-21017 is a high-severity vulnerability in Adobe Acrobat Reader, classified under Heap-based Buffer Overflow. CVSS score: 8.8/10. Published 2021-02-11.
How severe is CVE-2021-21017?: High severity. CVSS v3 base score is 8.8 out of 10.
Is CVE-2021-21017 known to be exploited?: Yes. CVE-2021-21017 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2021-11-03), indicating it is being actively exploited. 22 public proof-of-concept repositories are indexed.