Cisco ASA 9.3(1.50)/9.3(2.100)/9.3(3)/9.4(1) uRPF Validation Firewall input validation

CVSS Meta Temp Score
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CTI Interest Score
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6.7$5k-$25k0.00

Summaryinfo

A vulnerability, which was classified as critical, has been found in Cisco ASA 9.3(1.50)/9.3(2.100)/9.3(3)/9.4(1). Impacted is an unknown function of the component uRPF Validation. This manipulation causes input validation (Firewall). This vulnerability is handled as CVE-2015-4321. There is not any exploit available.

Detailsinfo

A vulnerability has been found in Cisco ASA 9.3(1.50)/9.3(2.100)/9.3(3)/9.4(1) (Firewall Software) and classified as critical. Affected by this vulnerability is an unknown functionality of the component uRPF Validation. The manipulation with an unknown input leads to a input validation vulnerability (Firewall). The CWE definition for the vulnerability is CWE-20. The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly. As an impact it is known to affect confidentiality, integrity, and availability.

The weakness was released 08/12/2015 with Cisco as 40440 / CSCuv60724 as confirmed vulnerability alert (Website). It is possible to read the advisory at tools.cisco.com. This vulnerability is known as CVE-2015-4321 since 06/04/2015. The attack can be launched remotely. The exploitation doesn't need any form of authentication. The technical details are unknown and an exploit is not publicly available. The pricing for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 11/24/2024). The advisory points out:

A vulnerability in the Unicast Reverse Path Forwarding (uRPF) feature in the Cisco Adaptive Security Appliance (ASA) could allow an unauthenticated, remote attacker to bypass the uRPF validation checks. The vulnerability is due to incorrect uRPF validation where IP packets from an outside interface, whose IP address is both in the ASA routing table and associated with an internal interface, are not dropped. An attacker could exploit this vulnerability by sending spoofed IP packets to the ASA in a subnet range that should be dropped. An exploit could allow the attacker to bypass uRPF validation on the ASA and the packet will be incorrectly forwarded on the internal network. Cisco has confirmed the vulnerability; however, software updates are not available.

The commercial vulnerability scanner Qualys is able to test this issue with plugin 43034 (Cisco ASA Unicast Reverse Path Forwarding Bypass Vulnerability (CSCuv60724)).

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the databases at X-Force (105519), SecurityFocus (BID 76325†), SecurityTracker (ID 1033265†) and Vulnerability Center (SBV-51971†). Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.3
VulDB Meta Temp Score: 6.7

VulDB Base Score: 7.3
VulDB Temp Score: 6.7
VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv2info

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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
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NVD Base Score: 🔍

Exploitinginfo

Name: Firewall
Class: Input validation / Firewall
CWE: CWE-20
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Status: Unproven

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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OpenVAS ID: 800316
OpenVAS Name: Cisco ASA uRFP Bypass Vulnerability
OpenVAS File: 🔍
OpenVAS Family: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔍

Timelineinfo

06/04/2015 🔍
08/12/2015 +69 days 🔍
08/12/2015 +0 days 🔍
08/12/2015 +0 days 🔍
08/13/2015 +1 days 🔍
08/13/2015 +0 days 🔍
08/16/2015 +3 days 🔍
08/20/2015 +4 days 🔍
11/24/2024 +3384 days 🔍

Sourcesinfo

Vendor: cisco.com

Advisory: 40440 / CSCuv60724
Organization: Cisco
Status: Confirmed

CVE: CVE-2015-4321 (🔍)
GCVE (CVE): GCVE-0-2015-4321
GCVE (VulDB): GCVE-100-77071
X-Force: 105519 - Cisco Adaptive Security Appliance security bypass
SecurityFocus: 76325 - Cisco Adaptive Security Appliance Software CVE-2015-4321 Security Bypass Vulnerability
SecurityTracker: 1033265 - Cisco ASA Lets Remote Users Bypass uRPF Validation on the Target System
Vulnerability Center: 51971 - Cisco Adaptive Security Appliance (ASA) Remote Security Bypass via Crafted IP Packets, Medium

Entryinfo

Created: 08/13/2015 10:34
Updated: 11/24/2024 10:58
Changes: 08/13/2015 10:34 (60), 10/14/2017 11:30 (14), 06/09/2022 11:31 (3), 11/24/2024 10:58 (16)
Complete: 🔍
Cache ID: 216::103

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