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CVE-2021-31402

24
FAUCET Score

CVE-2021-31402 is a CRLF injection vulnerability affecting version 4.0.0 of the Dart dio package, specifically impacting flutterchina dio. This high-severity vulnerability (CVSS 7.5) allows an unauthenticated attacker to inject carriage return and line feed characters if they can control the HTTP method string, potentially leading to HTTP response splitting or other malicious behavior. While no public exploits or Metasploit modules are available, and there is minimal community discussion or media coverage, the vulnerability remains a concern due to its potential for high impact on confidentiality.

Impacted Technologies

VendorProductVersion(s)CPE
>= 4.0.0, < 5.0.0CPE matchmatch criteria
cpe:2.3:a:flutterchina:dio:*:*:*:*:*:dart:*:*

CVSS Data

CVSS version used by this source: 3.1

7.5HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
NONE
Availability Impact
NONE
Exploitability Score
3.9
Impact Score
3.6
CvssVersion
3.1

Exploit Intelligence

EPSS Score
1.16%
Probability of exploitation in next 30 days
EPSS Percentile
63.8%
Percentile rank of EPSS score among Peer Group
As of 2026-07-28
Model: v2026.06.15
This CVE's current EPSS score of 0.0116 is in the 42nd percentile among its peer group of 51,553 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.1 Bluesky, 0.1 Mastodon, and 0.4 GitHub mentions.

Media Mentions

No media coverage found for this CVE.

The average CVE in this peer group has 0.1 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Patch Available

Vendor Patches (1)

pubpatch availablevia ghsa
Product: dioFixed in: 5.0.0

Vendor Advisories (1)

pubGHSA-9324-jv53-9cc8high

dio vulnerable to CRLF injection with HTTP method string

Mar 21, 2023

References

github.com / flutterchina/dio/issues/1130
ExploitIssue TrackingThird Party Advisory