strongSwan 4.5.0 < 6.0.5 EAP-TTLS AVP Parsing Integer Underflow

Summary

CVECVE-2026-25075
StatePUBLISHED
AssignerVulnCheck
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-03-23 19:16:39 UTC
Updated2026-05-04 19:16:02 UTC
DescriptionstrongSwan versions 4.5.0 prior to 6.0.5 contain an integer underflow vulnerability in the EAP-TTLS AVP parser that allows unauthenticated remote attackers to cause a denial of service by sending crafted AVP data with invalid length fields during IKEv2 authentication. Attackers can exploit the failure to validate AVP length fields before subtraction to trigger excessive memory allocation or NULL pointer dereference, crashing the charon IKE daemon.

Risk And Classification

Primary CVSS: v4.0 8.7 HIGH from [email protected]

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS: 0.002340000 probability, percentile 0.461270000 (date 2026-05-05)

Problem Types: CWE-191 | CWE-476 | CWE-191 CWE-191: Integer Underflow (Wrap or Wraparound) | CWE-476 NULL Pointer Dereference (CWE-476)


VersionSourceTypeScoreSeverityVector
4.0[email protected]Secondary8.7HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/C...
4.0CNACVSS8.7HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
3.1[email protected]Secondary7.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
3.1CNACVSS7.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS v4.0 Breakdown

Attack Vector
Network
Attack Complexity
Low
Attack Requirements
None
Privileges Required
None
User Interaction
None
Confidentiality
None
Integrity
None
Availability
High
Sub Conf.
None
Sub Integrity
None
Sub Availability
None

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

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

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA StrongSwan StrongSwan affected 4.5.0 6.0.5 semver Not specified

References

ReferenceSourceLinkTags
www.vulncheck.com/advisories/strongswan-eap-ttls-avp-parsing-integer-underflow [email protected] www.vulncheck.com
y637f9qq2x.com/posts/cve-2026-25075 [email protected] y637f9qq2x.com
www.strongswan.org/blog/2026/03/23/strongswan-6.0.5-released.html [email protected] www.strongswan.org
lists.debian.org/debian-lts-announce/2026/03/msg00016.html af854a3a-2127-422b-91ae-364da2661108 lists.debian.org
www.strongswan.org/blog/2026/03/23/strongswan-vulnerability-(cve-2026-25075).html [email protected] www.strongswan.org
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Vendor Comments And Credit

Discovery Credit

CNA: Kazuma Matsumoto, a security researcher at GMO Cybersecurity by IERAE, Inc. (en)

CNA: VulnCheck (en)

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