Cisco Email Security Appliance SMIME input validation

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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7.4$0-$5k0.00

A vulnerability classified as problematic has been found in Cisco Email Security Appliance (Anti-Malware Software) (affected version unknown). This affects an unknown functionality of the component SMIME Handler. The manipulation with an unknown input leads to a input validation vulnerability. CWE is classifying the issue as 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. This is going to have an impact on availability. The summary by CVE is:

A vulnerability in the Secure/Multipurpose Internet Mail Extensions (S/MIME) Decryption and Verification or S/MIME Public Key Harvesting features of Cisco AsyncOS Software for Cisco Email Security Appliance (ESA) could allow an unauthenticated, remote attacker to cause an affected device to corrupt system memory. A successful exploit could cause the filtering process to unexpectedly reload, resulting in a denial of service (DoS) condition on the device. The vulnerability is due to improper input validation of S/MIME-signed emails. An attacker could exploit this vulnerability by sending a malicious S/MIME-signed email through a targeted device. If Decryption and Verification or Public Key Harvesting is configured, the filtering process could crash due to memory corruption and restart, resulting in a DoS condition. The software could then resume processing the same S/MIME-signed email, causing the filtering process to crash and restart again. A successful exploit could allow the attacker to cause a permanent DoS condition. This vulnerability may require manual intervention to recover the ESA.

The bug was discovered 01/09/2019. The weakness was disclosed 01/10/2019 with Cisco as cisco-sa-20190109-esa-dos as confirmed advisory (Website). The advisory is shared at tools.cisco.com. This vulnerability is uniquely identified as CVE-2018-15453 since 08/17/2018. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 06/26/2023).

The vulnerability scanner Nessus provides a plugin with the ID 121248 (Cisco Email Security Appliance Multiple DoS Vulnerabilities (cisco-sa-20190109-esa-dos / cisco-sa-20190109-esa-url-dos)), 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 c. The commercial vulnerability scanner Qualys is able to test this issue with plugin 316363 (Cisco Email Security Appliance Memory Corruption Denial of Service Vulnerability(cisco-sa-20190109-esa-dos)).

Upgrading eliminates this vulnerability. A possible mitigation has been published before and not just after the disclosure of the vulnerability.

The vulnerability is also documented in the databases at Tenable (121248) and SecurityFocus (BID 106511†). The entry VDB-129001 is pretty similar.

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB CVSS-B Score: 🔍
VulDB CVSS-BT Score: 🔍
VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.5
VulDB Meta Temp Score: 7.4

VulDB Base Score: 5.3
VulDB Temp Score: 5.1
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 8.6
NVD Vector: 🔍

CNA Base Score: 8.6
CNA Vector (Cisco Systems, Inc.): 🔍

CVSSv2info

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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍

Exploitinginfo

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

Local: No
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Nessus ID: 121248
Nessus Name: Cisco Email Security Appliance Multiple DoS Vulnerabilities (cisco-sa-20190109-esa-dos / cisco-sa-20190109-esa-url-dos)
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Timelineinfo

08/17/2018 🔍
01/09/2019 +145 days 🔍
01/09/2019 +0 days 🔍
01/09/2019 +0 days 🔍
01/10/2019 +1 days 🔍
01/10/2019 +0 days 🔍
01/11/2019 +1 days 🔍
01/18/2019 +7 days 🔍
06/26/2023 +1620 days 🔍

Sourcesinfo

Vendor: cisco.com

Advisory: cisco-sa-20190109-esa-dos
Organization: Cisco
Status: Confirmed

CVE: CVE-2018-15453 (🔍)
SecurityFocus: 106511 - Cisco AsyncOS for Email Security Appliance CVE-2018-15453 Remote Denial of Service Vulnerability

See also: 🔍

Entryinfo

Created: 01/11/2019 07:42 AM
Updated: 06/26/2023 09:09 AM
Changes: 01/11/2019 07:42 AM (70), 04/28/2020 02:22 PM (6), 06/26/2023 09:09 AM (14)
Complete: 🔍
Cache ID: 18:9BD:40

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