Cyber Resilience

CVE-2021-38000

Open Redirect in Debian Linux 10.0 … 11.0

CISA KEVActive ExploitationEUVD ExploitedPublic PoCOpen Redirect
Published
23 November 2021
Modified
24 October 2025
KEV Added
03 November 2021
CVSS Score v3.1 6.1
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
EPSS Score 0.047 91th percentile
Risk Priority 75 floored blend · peak EPSS

Summary

CVE-2021-38000 is a medium-severity Open Redirect (CWE-601) vulnerability in Debian Debian Linux. Its CVSS base score is 6.1 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 9% 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.

The vulnerability CVE-2021-38000 stems from insufficient validation of untrusted input in Intents in Google Chrome on Android prior to version 95.0.4638.69. It is tracked under CWE-601 and CWE-20 and carries a CVSS 3.1 score of 6.1 reflecting network attack vector, low complexity, no required privileges, required user interaction, and changed scope with limited confidentiality and integrity impact.

A remote attacker can exploit the flaw by serving a crafted HTML page that triggers an arbitrary redirect of the victim's browser to a malicious URL. The attack succeeds without further privileges once the page is rendered, allowing the adversary to direct users to attacker-controlled destinations.

Chrome release notes and distribution advisories state that the issue is resolved by updating to Chrome 95.0.4638.69 or later; Fedora and Debian have issued corresponding package updates to enforce the patched version. No information on observed in-the-wild exploitation is supplied in the referenced sources.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

Insufficient validation of untrusted input in Intents in Google Chrome on Android prior to 95.0.4638.69 allowed a remote attacker to arbitrarily browser to a malicious URL via a crafted HTML page.

CWE(s)
KEV Date Added
03 November 2021

Related Threats

MITRE ATT&CK Enterprise Techniques

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.
T1036.001 Invalid Code Signature Stealth
Adversaries may attempt to mimic features of valid code signatures to increase the chance of deceiving a user, analyst, or tool.
T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
T1566 Phishing Initial Access
Adversaries may send phishing messages to gain access to victim systems.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2022-3075Same product: Fedoraproject Fedoraboth on KEV
CVE-2023-4357Same product: Debian Debian Linux
CVE-2022-2856Same product: Fedoraproject Fedoraboth on KEV
CVE-2020-0041Same product: Google Androidboth on KEV
CVE-2025-6558Same product: Debian Debian Linuxboth on KEV
CVE-2018-7600Same product: Debian Debian Linuxboth on KEV
CVE-2023-30631Same product: Debian Debian Linux
CVE-2024-31309Same product: Debian Debian Linux
CVE-2024-24549Same product: Debian Debian Linux
CVE-2026-13995Same product: Google Android

Affected Assets

google
chrome
≤ 95.0.4638.69
fedoraproject
fedora
34
debian
debian linux
10.0, 11.0

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 6 hardening rules · 3 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V3.7.2

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.

addresses: CWE-20 CWE-601

Directly implements checks on information inputs to reject invalid data before processing.

addresses: CWE-601

Security awareness includes verifying URLs and avoiding untrusted redirects that lead to malicious sites.

addresses: CWE-20

Security testing and developer training directly verify and enforce proper input validation, reducing exploitability of injection and malformed-data weaknesses.

addresses: CWE-20

Security testing and evaluation at multiple SDLC stages directly detects missing or flawed input validation, with the required remediation process ensuring fixes are applied.

addresses: CWE-20

Spam protection mechanisms perform filtering and detection on inbound/outbound messages, directly compensating for missing or weak input validation of unsolicited content.

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 SDLC practices directly require input validation and untrusted-redirect controls that prevent CWE-601.

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.

finds

Testing against a defined set of requirements and using code review plus vulnerability scanning forces validation of inputs and handling of unanticipated conditions, reducing the chance that malformed data will be accepted.

mitigates

Preventing access to attacker-controlled or malicious sites stops users from being redirected to untrusted locations via open-redirect or phishing links.

prevents

Secure-coding guidelines and mandatory security testing (including code scans) compel developers to validate and sanitize inputs at design and implementation time, lowering the incidence of malformed or malicious data reaching downstream components.

prevents

Mandating input controls that include integrity checks and input validation ensures that untrusted data is examined before use, blocking the root cause of many injection and malformed-data weaknesses.

prevents

Security-by-design principles explicitly call for data validation and sanitization at every layer, reducing the chance that malformed or malicious input will be processed without scrutiny.

prevents

Requiring language-specific secure coding standards, peer review, SAST and documented mitigation of common programming errors forces validation of all inputs before they are trusted.

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).

RHEL 8 (1 rule)
  • V-230265 RHEL 8 must prevent the installation of software, patches, service packs, device drivers, or operating system components of local packages without verification they have been digitally signed using a certificate that is issued by a Certificate Authority (CA) that is recognized and approved by the organization. prevents CWE-20

References