Feed aggregator

Vulnerability in Java Deserialization Affecting Cisco Products

Cisco Security Advisories - Mon, 2019-01-07 17:53
A vulnerability in the Java deserialization used by the Apache Commons Collections (ACC) library could allow an unauthenticated, remote attacker to execute arbitrary code.

The vulnerability is due to insecure deserialization of user-supplied content by the affected software. An attacker could exploit this vulnerability by submitting crafted input to an application on a targeted system that uses the ACC library. After the vulnerable library on the affected system deserializes the content, the attacker could execute arbitrary code on the system, which could be used to conduct further attacks.

On November 6, 2015, Foxglove Security Group published information about a remote code execution vulnerability that affects multiple releases of the ACC library. The report contains detailed proof-of-concept code for a number of applications, including WebSphere Application Server, JBoss, Jenkins, OpenNMS, and WebLogic. This is a remotely exploitable vulnerability that allows an attacker to inject any malicious code or execute any commands that exist on the server. A wide range of potential impacts includes allowing the attacker to obtain sensitive information.

Object serialization is a technique that many programming languages use to convert an object into a sequence of bits for transfer purposes. Deserialization is a technique that reassembles those bits back to an object. This vulnerability occurs in Java object serialization for network transport and object deserialization on the receiving side.

Many applications accept serialized objects from the network without performing input validation checks before deserializing it. Crafted serialized objects can therefore lead to execution of arbitrary attacker code.

Although the problem itself is in the serialization and deserialization functionality of the Java programming language, the ACC library is known to be affected by this vulnerability. Any application or application framework could be vulnerable if it uses the ACC library and deserializes arbitrary, user-supplied Java serialized data.

Additional details about the vulnerability are available at the following links:

Official Vulnerability Note from CERT
Foxglove Security
Apache Commons Statement
Oracle Security Alert

Cisco will release software updates that address this vulnerability. There are no workarounds that address this vulnerability.

This advisory is available at the following link:
Security Impact Rating: High
CVE: CVE-2015-6420
Categories: Security Alerts

Multiple Vulnerabilities in OpenSSL Affecting Cisco Products: September 2016

Cisco Security Advisories - Wed, 2018-12-19 14:58
On September 22, 2016, the OpenSSL Software Foundation released an advisory that describes 14 vulnerabilities. Of these 14 vulnerabilities, the OpenSSL Software Foundation classifies one as “Critical Severity,” one as “Moderate Severity,” and the other 12 as “Low Severity.”

Subsequently, on September 26, the OpenSSL Software Foundation released an additional advisory that describes two new vulnerabilities. These vulnerabilities affect the OpenSSL versions that were released to address the vulnerabilities disclosed in the previous advisory. One of the new vulnerabilities was rated as “High Severity” and the other as “Moderate Severity.”

Of the 16 released vulnerabilities:
  • Fourteen track issues that could result in a denial of service (DoS) condition
  • One (CVE-2016-2183, aka SWEET32) tracks an implementation of a Birthday attack against Transport Layer Security (TLS) block ciphers that use a 64-bit block size that could result in loss of confidentiality
  • One (CVE-2016-2178) is a timing side-channel attack that, in specific circumstances, could allow an attacker to derive the private DSA key that belongs to another user or service running on the same system

Five of the 16 vulnerabilities exclusively affect the recently released OpenSSL versions that are part of the 1.1.0 release series, which has not yet been integrated into any Cisco product.

This advisory is available at the following link:
Security Impact Rating: Medium
CVE: CVE-2016-2177,CVE-2016-2178,CVE-2016-2179,CVE-2016-2180,CVE-2016-2181,CVE-2016-2182,CVE-2016-2183,CVE-2016-6302,CVE-2016-6303,CVE-2016-6304,CVE-2016-6305,CVE-2016-6306,CVE-2016-6307,CVE-2016-6308,CVE-2016-6309,CVE-2016-7052
Categories: Security Alerts

Cisco Adaptive Security Appliance Software Privilege Escalation Vulnerability

Cisco Security Advisories - Wed, 2018-12-19 14:00

A vulnerability in the authorization subsystem of Cisco Adaptive Security Appliance (ASA) Software could allow an authenticated, but unprivileged (levels 0 and 1), remote attacker to perform privileged actions by using the web management interface.

The vulnerability is due to improper validation of user privileges when using the web management interface. An attacker could exploit this vulnerability by sending specific HTTP requests via HTTPS to an affected device as an unprivileged user. An exploit could allow the attacker to retrieve files (including the running configuration) from the device or to upload and replace software images on the device.

Cisco has released software updates that address this vulnerability. There are workarounds that address this vulnerability.

This advisory is available at the following link:

Security Impact Rating: High
CVE: CVE-2018-15465
Categories: Security Alerts

Cisco Energy Management Suite Default PostgreSQL Password Vulnerability

Cisco Security Advisories - Tue, 2018-12-04 14:00

A vulnerability in the configuration of a local database installed as part of the Cisco Energy Management Suite (CEMS) could allow an authenticated, local attacker to access and alter confidential data.

The vulnerability is due to the installation of the PostgreSQL database with unchanged default access credentials. An attacker could exploit this vulnerability by logging in to the machine where CEMS is installed and establishing a local connection to the database.

The fix for this vulnerability randomizes the database access password in new installations; however, the fix will not change the password for existing installations. Users are required to manually change the password, as documented in the Workarounds section of this advisory.

There are workarounds that address this vulnerability.

This advisory is available at the following link:

Security Impact Rating: Medium
CVE: CVE-2018-0468
Categories: Security Alerts

AA18-337A: SamSam Ransomware

US-CERT - Mon, 2018-12-03 08:18
Original release date: December 03, 2018

The Department of Homeland Security (DHS) National Cybersecurity and Communications Integration Center (NCCIC) and the Federal Bureau of Investigation (FBI) are issuing this activity alert to inform computer network defenders about SamSam ransomware, also known as MSIL/Samas.A. Specifically, this product shares analysis of vulnerabilities that cyber actors exploited to deploy this ransomware. In addition, this report provides recommendations for prevention and mitigation.

The SamSam actors targeted multiple industries, including some within critical infrastructure. Victims were located predominately in the United States, but also internationally. Network-wide infections against organizations are far more likely to garner large ransom payments than infections of individual systems. Organizations that provide essential functions have a critical need to resume operations quickly and are more likely to pay larger ransoms.

The actors exploit Windows servers to gain persistent access to a victim’s network and infect all reachable hosts. According to reporting from victims in early 2016, cyber actors used the JexBoss Exploit Kit to access vulnerable JBoss applications. Since mid-2016, FBI analysis of victims’ machines indicates that cyber actors use Remote Desktop Protocol (RDP) to gain persistent access to victims’ networks. Typically, actors either use brute force attacks or stolen login credentials. Detecting RDP intrusions can be challenging because the malware enters through an approved access point.

After gaining access to a particular network, the SamSam actors escalate privileges for administrator rights, drop malware onto the server, and run an executable file, all without victims’ action or authorization. While many ransomware campaigns rely on a victim completing an action, such as opening an email or visiting a compromised website, RDP allows cyber actors to infect victims with minimal detection.

Analysis of tools found on victims’ networks indicated that successful cyber actors purchased several of the stolen RDP credentials from known darknet marketplaces. FBI analysis of victims’ access logs revealed that the SamSam actors can infect a network within hours of purchasing the credentials. While remediating infected systems, several victims found suspicious activity on their networks unrelated to SamSam. This activity is a possible indicator that the victims’ credentials were stolen, sold on the darknet, and used for other illegal activity.

SamSam actors leave ransom notes on encrypted computers. These instructions direct victims to establish contact through a Tor hidden service site. After paying the ransom in Bitcoin and establishing contact, victims usually receive links to download cryptographic keys and tools to decrypt their network.

Technical Details

NCCIC recommends organizations review the following SamSam Malware Analysis Reports. The reports represent four SamSam malware variants. This is not an exhaustive list.

For general information on ransomware, see the NCCIC Security Publication at https://www.us-cert.gov/security-publications/Ransomware.


DHS and FBI recommend that users and administrators consider using the following best practices to strengthen the security posture of their organization's systems. System owners and administrators should review any configuration changes before implementation to avoid unwanted impacts.

  • Audit your network for systems that use RDP for remote communication. Disable the service if unneeded or install available patches. Users may need to work with their technology venders to confirm that patches will not affect system processes.
  • Verify that all cloud-based virtual machine instances with public IPs have no open RDP ports, especially port 3389, unless there is a valid business reason to keep open RDP ports. Place any system with an open RDP port behind a firewall and require users to use a virtual private network (VPN) to access that system.
  • Enable strong passwords and account lockout policies to defend against brute force attacks.
  • Where possible, apply two-factor authentication.
  • Regularly apply system and software updates.
  • Maintain a good back-up strategy.
  • Enable logging and ensure that logging mechanisms capture RDP logins. Keep logs for a minimum of 90 days and review them regularly to detect intrusion attempts.
  • When creating cloud-based virtual machines, adhere to the cloud provider’s best practices for remote access.
  • Ensure that third parties that require RDP access follow internal policies on remote access.
  • Minimize network exposure for all control system devices. Where possible, disable RDP on critical devices.
  • Regulate and limit external-to-internal RDP connections. When external access to internal resources is required, use secure methods such as VPNs. Of course, VPNs are only as secure as the connected devices.
  • Restrict users' ability (permissions) to install and run unwanted software applications.
  • Scan for and remove suspicious email attachments; ensure the scanned attachment is its "true file type" (i.e., the extension matches the file header).
  • Disable file and printer sharing services. If these services are required, use strong passwords or Active Directory authentication.

Additional information on malware incident prevention and handling can be found in Special Publication 800-83, Guide to Malware Incident Prevention and Handling for Desktops and Laptops, from the National Institute of Standards and Technology.[1]

Contact Information

To report an intrusion and request resources for incident response or technical assistance, contact NCCIC, FBI, or the FBI’s Cyber Division via the following information:


DHS strives to make this report a valuable tool for our partners and welcomes feedback on how this publication could be improved. You can help by answering a few short questions about this report at the following URL: https://www.us-cert.gov/forms/feedback.

References Revisions
  • December 3, 2018: Initial version

This product is provided subject to this Notification and this Privacy & Use policy.

Categories: Security Alerts


Subscribe to Willing Minds aggregator