ZDI-CAN-21334: Adobe Acrobat Reader DC Font Parsing Out-Of-Bounds Write Remote Code Execution Vulnerability
Adobe Acrobat Reader versions 23.003.20244 (and earlier) and 20.005.30467 (and earlier) are affected by an out-of-bounds write vulnerability that could result in 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.
- Published
- Aug 10, 2023
- Updated
- Jun 17, 2026
- EPSS
- 2.5% · 84th percentile
- CWE
- CWE-787
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Report tools
Action score
32
Monitor
Low priority for now.
- CVSS
- 31 / 40 · 7.8 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 1 / 30 · 2.5%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- 7.8
- CNA · adobe
- 7.8
- agree
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Affected systems
| Vendor | Product | CPE |
|---|---|---|
| adobe | acrobat dc | cpe:2.3:a:adobe:acrobat_dc |
| adobe | acrobat reader dc | cpe:2.3:a:adobe:acrobat_reader_dc |
| adobe | acrobat | cpe:2.3:a:adobe:acrobat |
| adobe | acrobat reader | cpe:2.3:a:adobe:acrobat_reader |
| apple | macos | cpe:2.3:o:apple:macos |
| microsoft | windows | cpe:2.3:o:microsoft:windows |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- adobe acrobat20.001.30005 and later · up to 20.005.30516.10516 inclusive
- adobe acrobat20.001.30005 and later · before 20.005.30514.10514
- adobe acrobat dc15.008.20082 and later · before 23.003.20269
- adobe acrobat reader20.001.30005 and later · before 20.005.30516.10516
- adobe acrobat reader20.001.30005 and later · before 20.005.30514.10514
- adobe acrobat reader dc15.008.20082 and later · before 23.003.20269
Versions reported by the vendor
Affected version ranges reported by the assigning authority (adobe). Independent of NVD's CPE analysis and usually ahead of it.
Adobe Acrobat Reader
- up to and including 23.003.20244affected · semver
Same product
adobe: all recordsOther highest-scoring records for the same primary product.
- CVE-2021-28550Adobe Acrobat Reader use after free vulnerability could lead to arbitrary code executionKEV81Now
- CVE-2023-21608Adobe Acrobat Reader DC resetForm Use-After-Free Remote Code Execution VulnerabilityKEV79This week
- CVE-2020-9715Adobe Acrobat and Reader versions 2020.009.20074 and earlier, 2020.001.30002, 2017.011.30171 and earlier, and 2015.006.30523 and earlier havKEV76This week
- CVE-2018-4990Adobe Acrobat and Reader versions 2018.011.20038 and earlier, 2017.011.30079 and earlier, and 2015.006.30417 and earlier have a Double Free KEV76This week
- CVE-2026-34621Acrobat Reader | Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution') (CWE-1321)KEV65This week
- CVE-2018-4993Adobe Acrobat and Reader versions 2018.011.20038 and earlier, 2017.011.30079 and earlier, and 2015.006.30417 and earlier have an NTLM SSO ha56Plan
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
No fix version is recorded for this entry. Check the references for vendor advisories.
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
The product’s vendor appears in a public program. Matched by name; verify the scope text in the program.
Technical details
Attack conditions
- Someone with local access to the system can trigger it.
- No account or password is required.
- A user must open a link or visit a page.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- high · data can be read
- Integrity
- high · data or configuration can be modified
- Availability
- high · the service can be disrupted
- Attack vector
- Local
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- High
Weakness class (CWE)
CWE-787 · Out-of-bounds WriteCVSS vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
nvd-primary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for all 385,000+ vulnerabilities; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpChange log
No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.
References
Vendor advisories and official records. Exploit/PoC links are deliberately left out.