Security readout for executives and security teams
Plain-English summary
A malicious web page could trigger a memory corruption bug in Chrome’s Reader Mode before version 90.0.4430.212. This is a browser exposure where normal web browsing is the entry point. The provided sources do not show active exploitation or a CVSS score.
Executive priority
Treat as a high-priority endpoint patching item because browsers process untrusted web content. Urgency is reduced by lack of cited active exploitation, but outdated browsers remain a common business risk.
Technical view
CVE-2021-30518 is a heap buffer overflow in Google Chrome Reader Mode. Chrome versions prior to 90.0.4430.212 could allow a remote attacker to potentially exploit heap corruption via a crafted HTML page. Public details are limited in the source bundle.
Likely exposure
Endpoints are exposed if they run Google Chrome before 90.0.4430.212. Exposure is most relevant on user workstations and managed browser fleets that can open untrusted HTML content.
Exploitation context
The source bundle describes remote exploitation through a crafted HTML page. CISA KEV status is false, and the supplied sources do not provide evidence of active exploitation.
Researcher notes
The public record gives a concise bug class, affected component, fixed Chrome version, and attack vector. It does not include CVSS, CWE mapping, exploit maturity, or detailed root-cause data in the supplied bundle.
Mitigation direction
- Update Google Chrome to 90.0.4430.212 or later.
- Apply applicable Gentoo or Fedora browser package updates where relevant.
- Confirm managed browser update policies enforce current stable versions.
- Review vendor guidance for any additional platform-specific remediation.
Validation and detection
- Inventory Chrome versions across managed endpoints.
- Flag Chrome installations earlier than 90.0.4430.212.
- Check Linux package advisory status for Gentoo and Fedora systems.
- Verify browser update telemetry after remediation.
- Confirm no exception policies pin affected browser versions.
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-2021-30518 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
- Unknown
- CVSS
- Not scored
- Known Exploited
- No
- Published
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 and timeline data
No CVSS vectors or timeline events were available in the normalized CVE source material.
Source materials
- CVE List V5 sourceCVE List V5
- https://chromereleases.googleblog.com/2021/05/stable-channel-update-for-desktop.htmlCVE reference · x_refsource_MISC
- https://crbug.com/1203590CVE reference · x_refsource_MISC
- GLSA-202107-06CVE reference · vendor-advisory, x_refsource_GENTOO
- FEDORA-2021-f94dadff78CVE reference · vendor-advisory, x_refsource_FEDORA
- FEDORA-2021-ca58c57bdfCVE reference · vendor-advisory, x_refsource_FEDORA
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.