Dark Reading is part of the Informa Tech Division of Informa PLC

This site is operated by a business or businesses owned by Informa PLC and all copyright resides with them.Informa PLC's registered office is 5 Howick Place, London SW1P 1WG. Registered in England and Wales. Number 8860726.

Risk

Bug Hits Popular IP-PBX Apps

Asterisk PBX and IAXclient, two of the most popular open-source VOIP applications, are vulnerable to attack

Users of two popular open-source VOIP applications could come under attack if they don't patch their software quickly, a security researcher said today.

The vulnerability could enable attackers to create buffer overflows in VOIP networks, effectively creating a denial-of-service attack on networks that use the software, according to Core Security Technologies, which discovered the threat.

Asterisk PBX, a widely used open-source application that provides private branch exchange features for VOIP networks, and IAX client, an open-source library that runs VOIP protocols for several IP software phones, are the two systems at risk. The two applications are widely used in small businesses where conventional IP-PBX software is too expensive. But Asterisk also serves as the underlying software for enterprise-level and service-provider products, such as Aspect Software's contact center application and SIPphone's Gizmo Project.

The two applications contain a design flaw in which they fail to check for malformed UDP packets, according to Ivan Arce, CTO at Core Security. "An attacker can easily create a buffer overflow by sending an abundance of packets that are too short," he says.

The open-source Asterisk group and Digium, which distributes Asterisk, have both made patches available for the vulnerability. However, like most open-source organizations, they have no automated means of distributing the patches, so they are encouraging users to come to them quickly for the updates.

Unpatched, the vulnerability could be serious for VOIP environments, because it is relatively easy to exploit. "If you're supporting VOIP, you have to let these [short] packets pass or risk losing service," Arce says. The Asterisk group agrees, stating that the vulnerability could lead to "random Asterisk server crashes via a relatively trivial exploit."

The vulnerability report deals another blow to VOIP security, which was rocked last week when two men were charged with stealing and reselling VOIP service from 15 service providers. (See Two Charged in VOIP Hacking Scandal.)

"I expect we'll see a lot more vulnerabilities like this in VOIP before we're through," Arce said. "VOIP is no different from any other IP traffic, and it is still relatively new. There will be a lot of bugs to work out."

— Tim Wilson, Site Editor, Dark Reading

Organizations mentioned in this story

  • Aspect Software
  • Asterisk organization
  • Core Security Technologies
  • Digium Inc.
  • SIPphone Inc.

    Tim Wilson is Editor in Chief and co-founder of Dark Reading.com, UBM Tech's online community for information security professionals. He is responsible for managing the site, assigning and editing content, and writing breaking news stories. Wilson has been recognized as one ... View Full Bio

    Comment  | 
    Print  | 
    More Insights
  • Comments
    Newest First  |  Oldest First  |  Threaded View
    44% of Security Threats Start in the Cloud
    Kelly Sheridan, Staff Editor, Dark Reading,  2/19/2020
    Zero-Factor Authentication: Owning Our Data
    Nick Selby, Chief Security Officer at Paxos Trust Company,  2/19/2020
    Register for Dark Reading Newsletters
    White Papers
    Video
    Cartoon
    Current Issue
    6 Emerging Cyber Threats That Enterprises Face in 2020
    This Tech Digest gives an in-depth look at six emerging cyber threats that enterprises could face in 2020. Download your copy today!
    Flash Poll
    How Enterprises Are Developing and Maintaining Secure Applications
    How Enterprises Are Developing and Maintaining Secure Applications
    The concept of application security is well known, but application security testing and remediation processes remain unbalanced. Most organizations are confident in their approach to AppSec, although others seem to have no approach at all. Read this report to find out more.
    Twitter Feed
    Dark Reading - Bug Report
    Bug Report
    Enterprise Vulnerabilities
    From DHS/US-CERT's National Vulnerability Database
    CVE-2020-9405
    PUBLISHED: 2020-02-26
    IBL Online Weather before 4.3.5a allows unauthenticated reflected XSS via the redirect page.
    CVE-2020-9406
    PUBLISHED: 2020-02-26
    IBL Online Weather before 4.3.5a allows unauthenticated eval injection via the queryBCP method of the Auxiliary Service.
    CVE-2020-9407
    PUBLISHED: 2020-02-26
    IBL Online Weather before 4.3.5a allows attackers to obtain sensitive information by reading the IWEBSERVICE_JSONRPC_COOKIE cookie.
    CVE-2020-9398
    PUBLISHED: 2020-02-25
    ISPConfig before 3.1.15p3, when the undocumented reverse_proxy_panel_allowed=sites option is manually enabled, allows SQL Injection.
    CVE-2015-5201
    PUBLISHED: 2020-02-25
    VDSM and libvirt in Red Hat Enterprise Virtualization Hypervisor (aka RHEV-H) 7-7.x before 7-7.2-20151119.0 and 6-6.x before 6-6.7-20151117.0 as packaged in Red Hat Enterprise Virtualization before 3.5.6 when VSDM is run with -spice disable-ticketing and a VM is suspended and then restored, allows r...