Cyber Resilience

CVE-2021-30632

Memory Safety in Fedoraproject Fedora 33 … 35

CISA KEVActive ExploitationEUVD ExploitedPublic PoCMemory Safety
Published
08 October 2021
Modified
24 October 2025
KEV Added
03 November 2021
CVSS Score v3.1 8.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS Score 0.65 99.2th percentile
Risk Priority 90 floored blend · peak EPSS

Summary

CVE-2021-30632 is a high-severity Out-of-bounds Write (CWE-787) vulnerability in Fedoraproject Fedora. Its CVSS base score is 8.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked in the top 0.8% of CVEs by exploit likelihood; CISA has added it to the Known Exploited Vulnerabilities catalog; a public proof-of-concept is referenced.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2021-30632 is an out-of-bounds write vulnerability in the V8 JavaScript engine affecting Google Chrome versions prior to 93.0.4577.82. The flaw is classified under CWE-787 and carries a CVSS 3.1 score of 8.8, indicating high impact on confidentiality, integrity, and availability.

A remote attacker can exploit the issue by serving a crafted HTML page to a victim, triggering heap corruption in the browser's JavaScript execution environment without requiring authentication.

Chrome stable channel updates and corresponding Fedora package advisories recommend upgrading to version 93.0.4577.82 or later to address the vulnerability. Public references also include a Chromium bug tracker entry and a technical report describing a JIT compiler type confusion trigger.

The provided Packet Storm reference points to a proof-of-concept exploit targeting the same code path.

EU & UK References

Vulnerability Data

Out of bounds write in V8 in Google Chrome prior to 93.0.4577.82 allowed a remote attacker to potentially exploit heap corruption via a crafted HTML page.

CWE(s)
CWE-787
KEV Date Added
03 November 2021

Related Threats

MITRE ATT&CK Enterprise Techniques

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
attack.mitre.org →
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
attack.mitre.org →
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
attack.mitre.org →
T1211 Exploitation for Stealth Stealth
Adversaries may exploit vulnerabilities to evade detection by hiding activity, suppressing logging, or operating within trusted or unmonitored components.
attack.mitre.org →
T1212 Exploitation for Credential Access Credential Access
Adversaries may exploit software vulnerabilities in an attempt to collect credentials.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2024-4761Same product: Fedoraproject Fedoraboth on KEV
CVE-2021-21220Same product: Fedoraproject Fedoraboth on KEV
CVE-2024-0517Same product: Fedoraproject Fedora
CVE-2024-5844Same product: Fedoraproject Fedora
CVE-2024-5499Same product: Fedoraproject Fedora
CVE-2024-2173Same product: Fedoraproject Fedora
CVE-2024-0223Same product: Fedoraproject Fedora
CVE-2023-1529Same product: Fedoraproject Fedora
CVE-2024-3157Same product: Fedoraproject Fedora
CVE-2021-21148Same product: Fedoraproject Fedoraboth on KEV

Affected Assets

google
chrome
≤ 93.0.4577.82
fedoraproject
fedora
33, 35

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

SI-16 Memory Protection
addresses: CWE-787

Out-of-bounds writes that corrupt control flow or inject shellcode are rendered non-executable by the same memory protections.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure-development practices (static analysis, bounds checking, code review) are the primary means of preventing out-of-bounds writes.

ID.RA-01 partial match
prevents

Vulnerability scanning and recording can discover out-of-bounds write flaws so they can be remediated.

PR.PS-02 partial match
prevents

Patching or replacing vulnerable software directly eliminates known instances of this coding weakness.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.29 Security testing in development and acceptance mostly match
finds

Security testing in development and acceptance can detect and prevent out-of-bounds write defects.

A.8.25 Secure development life cycle partial match
prevents

Secure development life cycle mandates practices that prevent out-of-bounds writes.

A.8.26 Application security requirements partial match
prevents

Application security requirements can specify bounds-checking and safe memory handling.

A.8.27 Secure system architecture and engineering principles partial match
prevents

Secure architecture and engineering principles reduce the likelihood of buffer overflows.

A.8.28 Secure coding partial match
prevents

Secure coding directly addresses out-of-bounds writes through language choice and coding standards.

A.8.32 Change management partial match
prevents

Change management can enforce review gates that catch unsafe memory operations before deployment.

References