Security readout for executives and security teams
Plain-English summary
This vulnerability affects Adobe Acrobat Reader and may expose restricted data held in application global variables or objects. The available source data rates it medium severity, with low confidentiality impact and no integrity or availability impact stated.
Executive priority
Treat as a moderate endpoint hygiene issue. It is not presented as actively exploited in the provided sources, but affected Reader installations should be updated through normal vulnerability management cycles.
Technical view
CVE-2021-28559 is a CWE-359 privacy violation in Acrobat Reader DC versions 2021.001.20150 and earlier, 2020.001.30020 and earlier, and 2017.011.30194 and earlier. The CVSS 3.1 vector is AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N.
Likely exposure
Organizations may be exposed where affected Acrobat Reader DC tracks remain installed on user workstations or shared systems. The bundle does not identify server products, mobile products, or non-Reader Adobe products as affected.
Exploitation context
The source bundle does not show CISA KEV listing or cited evidence of active exploitation. The CVSS vector indicates remote, unauthenticated, low-complexity exposure without user interaction, but only low confidentiality impact is specified.
Researcher notes
Evidence is limited to CVE metadata and Adobe’s referenced bulletin. The bundle does not provide exploit details, fixed version numbers, or practical indicators of compromise, so validation should focus on version exposure and vendor bulletin alignment.
Mitigation direction
- Review Adobe APSB21-29 for vendor-approved update guidance.
- Inventory Acrobat Reader DC versions across managed endpoints.
- Prioritize replacement or update of affected Reader versions.
- Check vendor guidance before relying on compensating controls.
Validation and detection
- Confirm installed Acrobat Reader versions against affected version thresholds.
- Verify patch status using endpoint management or software inventory data.
- Review Adobe APSB21-29 for fixed-version details.
- Document any systems that cannot be updated promptly.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-359: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupPrivilege behavior lookup
The CVE wording references privilege impact, so privilege escalation and authorization behavior review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2021-28559 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 5.3 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N3.91.4Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
5.3MediumVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://helpx.adobe.com/security/products/acrobat/apsb21-29.htmlCVE reference · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Exposure of Private Personal Information to an Unauthorized Actor
Exposure of Private Personal Information to an Unauthorized Actor represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.