dio vulnerable to CRLF injection with HTTP method string

published 2021-04-15 5 y ago modified 2026-06-17 4 mo ago also EUVD-2023-0955 , GHSA-9324-jv53-9cc8

cvss: 7.5; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 1.2%; EPSS 1.2% chance of exploitation in 30 days, percentile 67%
public exploits: 0; none known

The dio package 4.0.0 for Dart allows CRLF injection if the attacker controls the HTTP method string, a different vulnerability than CVE-2020-35669.

Patch / fix

fixed in 2 links 1

pub dio 5.0.0
flutterchina dio 5.0.0

github.com/cfug/dio@927f79e commit

Exploit prediction

1.17% chance of exploitation in the next 30 days, higher than 67% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

github.com https://github.com/flutterchina/dio/issues/1130 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
GitHub	3.1	7.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
NVD	3.1	7.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
NVD	2.0	5.0	AV:N/AC:L/Au:N/C:P/I:N/A:N

Affected packages

ecosystem	package	affected	fixed in
pub	dio	<5.0.0	5.0.0

Classification

Weakness

CWE-93 Improper Neutralization of CRLF Sequences
CWE-74 Improper Neutralization of Special Elements in Output Used by a Downstream Component

References

github.com /cfug/dio/commit/927f79e93ba39f3c3a12c190624a55653d577984
web
github.com /flutterchina/dio/issues/1130
web, exploit, issue-tracking, third-party-advisory
github.com /cfug/dio/security/advisories/GHSA-9324-jv53-9cc8
web
nvd.nist.gov /vuln/detail/CVE-2021-31402
advisory
github.com /cfug/dio/issues/1752
web
github.com /cfug/dio
package
osv.dev /GHSA-jwpw-q68h-r678
web
security.snyk.io /vuln/SNYK-PUB-DIO-5891148
web

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary