CVE-2021-0313Public exploitNetwork attack vector

Remote TextView denial of service via bidi controls

Published Jan 11, 2021 · Updated Aug 3, 2024

Denial of service in Android 8.0 through 11 allows remote attackers to permanently interrupt a TextView via crafted text. LayoutUtils::isWordBreakAfter fails to treat Unicode bidirectional control characters as word boundaries, leaving crafted text in one layout context. No authentication, privileges, or user interaction is required; processing the string can severely slow or crash the TextView.

CVSS severity7.5
High
EPSS probability1.68%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in Android 8.0 through 11 allows remote attackers to permanently interrupt a TextView via crafted text. LayoutUtils::isWordBreakAfter fails to treat Unicode bidirectional control characters as word boundaries, leaving crafted text in one layout context. No authentication, privileges, or user interaction is required; processing the string can severely slow or crash the TextView.

The record

CVE
CVE-2021-0313
Published
Jan 11, 2021
Updated
Aug 3, 2024
Vendor
Google Cloud
Product
Android
Classifications
CWE-20, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 11, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=Android-10
  2. Affected versionversion=Android-11
  3. Affected versionversion=Android-8.0
  4. Affected versionversion=Android-8.1
  5. Affected versionversion=Android-9

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Google Cloud · Androidversion=Android-10; version=Android-11; version=Android-8.0; version=Android-8.1; version=Android-9

Published CVSS scores

7.8NIST National Vulnerability DatabaseAV:N/AC:L/Au:N/C:N/I:N/A:C
7.5NIST National Vulnerability DatabaseCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-20Improper Input Validation
T1499.004Application or System Exploitation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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