strongSwan up to 5.0.4 XAuth/EAP asn1.c is_asn1 XAuth Username/EAP Identity memory corruption
CVSS Meta Temp Score | Current Exploit Price (≈) | CTI Interest Score |
---|---|---|
5.3 | $0-$5k | 0.00 |
A vulnerability classified as problematic has been found in strongSwan up to 5.0.4 (Network Encryption Software). Affected is the function is_asn1
in the library libstrongswan/asn1/asn1.c of the component XAuth/EAP Handler. The manipulation as part of a XAuth Username/EAP Identity leads to a memory corruption vulnerability. CWE is classifying the issue as CWE-119. The product performs operations on a memory buffer, but it can read from or write to a memory location that is outside of the intended boundary of the buffer. This is going to have an impact on availability. CVE summarizes:
The is_asn1 function in strongSwan 4.1.11 through 5.0.4 does not properly validate the return value of the asn1_length function, which allows remote attackers to cause a denial of service (segmentation fault) via a (1) XAuth username, (2) EAP identity, or (3) PEM encoded file that starts with a 0x04, 0x30, or 0x31 character followed by an ASN.1 length value that triggers an integer overflow.
The weakness was presented 07/29/2013 by Ewan Smythe as strongSwan Denial-of-Service Vulnerability (CVE-2013-5018) as confirmed blog post (Website). The advisory is shared for download at strongswan.org. This vulnerability is traded as CVE-2013-5018 since 07/30/2013. The exploitability is told to be difficult. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. Technical details and a public exploit are known.
After 3 days, there has been an exploit disclosed. It is declared as proof-of-concept. The vulnerability scanner Nessus provides a plugin with the ID 75115 (openSUSE Security Update : strongswan (openSUSE-SU-2013:1332-1)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family SuSE Local Security Checks. The commercial vulnerability scanner Qualys is able to test this issue with plugin 166641 (SUSE Enterprise Linux Security Update for Strongswan (SUSE-SU-2013:1866-1)).
Upgrading to version 5.1.0 eliminates this vulnerability. The upgrade is hosted for download at strongswan.org. Applying the patch 4.1.11-4.2.17_is_asn1.patch/4.3.0-5.0.4_is_asn1.patch is able to eliminate this problem. The bugfix is ready for download at download.strongswan.org. The best possible mitigation is suggested to be upgrading to the latest version. A possible mitigation has been published 3 days after the disclosure of the vulnerability.
The vulnerability is also documented in the databases at X-Force (86125) and Tenable (75115). See 11069 for similar entry.
Product
Type
Name
Version
License
CPE 2.3
CPE 2.2
CVSSv4
VulDB CVSS-B Score: 🔍VulDB CVSS-BT Score: 🔍
VulDB Vector: 🔍
VulDB Reliability: 🔍
CVSSv3
VulDB Meta Base Score: 5.9VulDB Meta Temp Score: 5.3
VulDB Base Score: 5.9
VulDB Temp Score: 5.3
VulDB Vector: 🔍
VulDB Reliability: 🔍
CVSSv2
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VulDB Base Score: 🔍
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VulDB Reliability: 🔍
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Exploiting
Class: Memory corruptionCWE: CWE-119
ATT&CK: Unknown
Local: No
Remote: Yes
Availability: 🔍
Access: Public
Status: Proof-of-Concept
EPSS Score: 🔍
EPSS Percentile: 🔍
Price Prediction: 🔍
Current Price Estimation: 🔍
0-Day | unlock | unlock | unlock | unlock |
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Today | unlock | unlock | unlock | unlock |
Nessus ID: 75115
Nessus Name: openSUSE Security Update : strongswan (openSUSE-SU-2013:1332-1)
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Port: 🔍
OpenVAS ID: 866838
OpenVAS Name: Fedora Update for strongswan FEDORA-2013-14481
OpenVAS File: 🔍
OpenVAS Family: 🔍
Qualys ID: 🔍
Qualys Name: 🔍
Threat Intelligence
Interest: 🔍Active Actors: 🔍
Active APT Groups: 🔍
Countermeasures
Recommended: UpgradeStatus: 🔍
Reaction Time: 🔍
0-Day Time: 🔍
Exposure Time: 🔍
Exploit Delay Time: 🔍
Upgrade: strongSwan 5.1.0
Patch: 4.1.11-4.2.17_is_asn1.patch/4.3.0-5.0.4_is_asn1.patch
Timeline
07/29/2013 🔍07/30/2013 🔍
08/01/2013 🔍
08/01/2013 🔍
08/01/2013 🔍
08/01/2013 🔍
08/01/2013 🔍
08/05/2013 🔍
08/26/2013 🔍
08/28/2013 🔍
06/13/2014 🔍
05/21/2021 🔍
Sources
Advisory: strongSwan Denial-of-Service Vulnerability (CVE-2013-5018)Researcher: Ewan Smythe
Status: Confirmed
Confirmation: 🔍
CVE: CVE-2013-5018 (🔍)
OVAL: 🔍
X-Force: 86125
Vulnerability Center: 41210 - strongSwan Before 5.1.0 Remote Denial of Service via Crafted Xauth Usernames, EAP Identities or PEM Encoded Files, High
SecurityFocus: 61564 - strongSwan 'is_asn1()' Function Denial of Service Vulnerability
Secunia: 54315 - strongSwan "is_asn1()" XAuth Username and EAP Identity Handling Denial of Servic, Moderately Critical
OSVDB: 95904
See also: 🔍
Entry
Created: 08/05/2013 14:36Updated: 05/21/2021 08:19
Changes: 08/05/2013 14:36 (85), 08/21/2017 08:44 (10), 05/21/2021 08:19 (3)
Complete: 🔍
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