Security readout for executives and security teams
Plain-English summary
Adobe Acrobat Reader for Windows had an installer DLL search-path weakness. A local, non-admin attacker who can place a malicious DLL and get a user to interact with the installer could run code as that user. This is an endpoint execution risk, not a remote internet-facing flaw.
Executive priority
Prioritize remediation through endpoint software management. The flaw is high impact but needs local positioning and user interaction, so it is less urgent than remotely exploitable perimeter issues.
Technical view
CVE-2021-35982 is CWE-427 in Acrobat Reader DC installer behavior on Windows. Affected versions include 2021.005.20060 and earlier, 2020.004.30006 and earlier, and 2017.011.30199 and earlier. CVSS 3.0 is 7.3: local attack, low complexity, low privileges, required user interaction, high impact.
Likely exposure
Organizations with Windows endpoints running affected Adobe Acrobat Reader DC versions, especially where older installers or Reader branches remain available.
Exploitation context
The source bundle does not show active exploitation, and CISA KEV status is false. Exploitation requires local access, user interaction, and DLL planting before code runs in the current user context.
Researcher notes
Focus validation on installed Reader versions, retained installer packages, and writable paths used by deployment workflows. The bundle names DLL hijacking but does not provide exploit artifacts or observed abuse evidence.
Mitigation direction
- Apply Adobe security updates referenced in APSB21-55.
- Upgrade beyond the affected Reader version lines listed for this CVE.
- Remove outdated Reader installers from shared folders and software portals.
- Restrict standard users from writing to software deployment locations.
- Check Adobe guidance if exact fixed builds are needed.
Validation and detection
- Inventory Windows endpoints for Acrobat Reader DC versions.
- Flag versions at or below the affected build numbers.
- Review software distribution shares for old Reader installers.
- Confirm endpoint controls restrict DLL writes near installers.
- Document whether APSB21-55 updates are deployed.
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-427: 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 lookupExecution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2021-35982 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
- High
- CVSS
- 7.3 (3.0)
- Known Exploited
- No
- Published
Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H
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:3.0/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H1.35.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.0 score
7.3HighVector: CVSS:3.0/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://helpx.adobe.com/security/products/acrobat/apsb21-55.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.
Uncontrolled Search Path Element
Uncontrolled Search Path Element represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.