Security readout for executives and security teams
Plain-English summary
CVE-2021-34457 is a Microsoft Windows information disclosure issue in Remote Access Connection Manager. A local, low-privileged user could potentially obtain sensitive information. It is not described as remote code execution, and the supplied sources do not show active exploitation.
Executive priority
Treat as a normal patch-management priority, not an emergency, unless affected systems allow many local users or cannot be patched. The key business risk is confidential information exposure after local access.
Technical view
The CVSS vector is local attack vector, low complexity, low privileges required, no user interaction, unchanged scope, and high confidentiality impact only. Affected systems include multiple Windows 10, Windows 7/8.1, Windows Server 2008, 2016, 2019, 2004, and 20H2 builds listed by Microsoft/CVE sources.
Likely exposure
Exposure is mainly Windows endpoints or servers running affected builds. Risk is higher on shared systems, terminal servers, or environments where untrusted local users have accounts. The bundle does not identify a network-exposed attack path.
Exploitation context
The source bundle marks KEV as false and provides no cited evidence of active exploitation. Exploitation requires local access with low privileges, so it is more relevant after initial access or on multi-user Windows systems.
Researcher notes
Public details in the supplied bundle are sparse: no CWE, no technical root cause, and no description of the exposed information. Do not infer exploitability beyond the CVSS vector and Microsoft/CVE affected-product data.
Mitigation direction
- Apply Microsoft security updates referenced by the MSRC advisory.
- Inventory affected Windows versions and builds listed in the CVE bundle.
- Prioritize shared Windows hosts and systems allowing local user access.
- Check Microsoft guidance for version-specific update requirements.
- Retire or isolate systems that cannot receive vendor updates.
Validation and detection
- Compare Windows asset builds against the affected CPE/build list.
- Verify patch compliance against the Microsoft CVE advisory.
- Confirm vulnerable hosts are not running unpatched affected builds.
- Review privileged or shared-access Windows systems first.
- Document exceptions for unsupported or update-blocked systems.
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.
CVE-2021-34457 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
- 5.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C
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:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C1.83.6Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
5.5MediumVector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C
Source materials
- CVE List V5 sourceCVE List V5
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-34457CVE 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.