CVE-2021-28550
Adobe Acrobat Reader use after free vulnerability could lead to arbitrary code execution
Exploited in the wild. In CISA KEV since 2021‑11‑03. A vendor fix is available.
What to do
The vendor has published a fix. Version details are below where the sources state them.
- Adobe Acrobat ReaderAffected: ≥ unspecified, ≤ 2020.001.30020Upgrade to: after 2020.001.30020Affected: ≥ unspecified, ≤ 2021.001.20150Upgrade to: after 2021.001.20150Affected: ≥ unspecified, ≤ 2017.011.30194Upgrade to: after 2017.011.30194Affected: ≥ unspecified, ≤ NoneUpgrade to: after NoneStated by: CVE record
- Adobe Acrobat DcAffected: ≥ 15.008.20082, ≤ 21.001.20150Upgrade to: after 21.001.20150Stated by: NVD
- Adobe Systems Inc. Adobe Acrobat Reader 2020Affected: до 2020.001.30025 Classic 2020Upgrade to: not statedStated by: BDU
Versions as the sources state them. Full version matrix after sign-in
Coverage timeline
0 publishersAdded to CISA KEV catalog
Sourced from public security reporting — each date is when it was published, not when it happened.
What it is
From the CVE record
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.
In plain language
No plain-language summary for this CVE yet.
Exploitation
Where each signal puts this CVE on the scale from published to confirmed exploited.
- CISA KEV
Listed as exploited in the wild since 2021-11-03.
US federal agencies must remediate by 2021-11-17.
Apply updates per vendor instructions.
- Public exploits
No public exploit or proof of concept found in the sources we track.
- EPSS
52% chance of exploitation activity in the next 30 days, which ranks it in the 99th percentile of scored CVEs.
Exploit Prediction Scoring System, FIRST.org. A probability, not a confirmation.
Lifecycle
8 events over 1757 days, from the signal feeds we watch.
- OpenVAS check added
- EPSS band changemoderate → high
- Patch availablerecord updated
- Added to CISA KEV
- Publishedweakness classified, att&ck mapped
Affected products
Technical detail
CVSS 3.1 vector
Open in the CVSS calculatorCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Scored 8.8 by NVD.
How it is reached
- Attack Vector NetworkExploitable remotely over the network without any special conditions
- Attack Complexity LowNo special conditions — the attack can be reliably reproduced
- Privileges Required NoneNo authentication required — anyone can exploit this
- User Interaction RequiredA user must click a link, open a file, or perform some action
Scope
- Scope UnchangedImpact is limited to the vulnerable component itself
Impact if exploited
- Confidentiality HighTotal information disclosure — all data in the component is compromised
- Integrity HighTotal loss of integrity — attacker can modify any data in the component
- Availability HighTotal denial of service — the component is completely unavailable
Weaknesses
ATT&CK techniques
Mapped from the weaknesses above (CWE to ATT&CK), not observed in attacks.
- Initial AccessT1190Exploit Public-Facing Applicationhigh confidence
- Privilege EscalationT1068Exploitation for Privilege Escalationhigh confidence
Sources
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