Feeds

Cisco visits top clients to warn of SNMP bugs

Door for possible DoS exploits

  • alert
  • submit to reddit

Next gen security for virtualised datacentres

Cisco has publicly disclosed a number of potentially devastating security vulnerabilities affecting the operating system used by its routers and switches.

In the most serious case, flaws in the way Cisco's Internetwork Operating System (IOS) implements Simple Network Management Protocol (SNMP), a standard for the remote administration of network devices, could leave the door open to fresh types of denial of service attacks.

Multiple versions of IOS contain several independent, but related, vulnerabilities involving the unexpected creation and exposure of SNMP community strings, which define how operating variables can be viewed or modified on a networked device.

"Knowledge of read-write community strings allows remote configuration of affected devices without authorisation, possibly without the awareness of the administrators of the device and resulting in a failure of integrity and a possible failure of availability," Cisco discloses in a security notice, available here.

Roy Hills, testing development director at security testing firm NTA Monitor, said: "What Cisco has said indicates there's potential for denial of service attack, the question is how easy this would be. Any real damage possible with the vulnerability depends on the scope of access and whether an exploit became posted."

According to Hills, the vulnerability is a "major issue" because so many devices will need to be modified, a particular headache for service providers.

The vulnerability affects almost all Cisco routers and switches, but not its voice gateways, optical switches or firewalls.

Cisco is taking the issue very seriously and took the highly unusual step of visiting its most important customers to discuss the issue beforehand, including one Register reader who told us he received a short-notice visit from three senior Cisco techies last week.

To fix the bugs, Cisco is offering free software upgrades for various versions of its operating system, all of which are affected by the problem. Pending the availability of some of these fixes, Cisco has suggested a workaround involving blocking SNMP access.

Separately, Cisco has warned that IOS contains a flaw which permits the successful prediction of TCP Initial Sequence Numbers; this makes it easier to forge messages that could allow crackers to break into systems.

However, exploitation of the vulnerability is only possible for TCP sessions which originate or terminate on the affected Cisco device itself, not on traffic flowing through it. More information on this bug is available here. ®

Related stories:
Cisco routers vulnerable to easy attack
Cisco 600 routers offer cracker fun

5 things you didn’t know about cloud backup

More from The Register

next story
The Return of BSOD: Does ANYONE trust Microsoft patches?
Sysadmins, you're either fighting fires or seen as incompetents now
Oracle reveals 32-core, 10 BEEELLION-transistor SPARC M7
New chip scales to 1024 cores, 8192 threads 64 TB RAM, at speeds over 3.6GHz
Microsoft: Azure isn't ready for biz-critical apps … yet
Microsoft will move its own IT to the cloud to avoid $200m server bill
Docker kicks KVM's butt in IBM tests
Big Blue finds containers are speedy, but may not have much room to improve
US regulators OK sale of IBM's x86 server biz to Lenovo
Now all that remains is for gov't offices to ban the boxes
Gartner's Special Report: Should you believe the hype?
Enough hot air to carry a balloon to the Moon
Flash could be CHEAPER than SAS DISK? Come off it, NetApp
Stats analysis reckons we'll hit that point in just three years
Dell The Man shrieks: 'We've got a Bitcoin order, we've got a Bitcoin order'
$50k of PowerEdge servers? That'll be 85 coins in digi-dosh
prev story

Whitepapers

Endpoint data privacy in the cloud is easier than you think
Innovations in encryption and storage resolve issues of data privacy and key requirements for companies to look for in a solution.
Implementing global e-invoicing with guaranteed legal certainty
Explaining the role local tax compliance plays in successful supply chain management and e-business and how leading global brands are addressing this.
Top 8 considerations to enable and simplify mobility
In this whitepaper learn how to successfully add mobile capabilities simply and cost effectively.
Solving today's distributed Big Data backup challenges
Enable IT efficiency and allow a firm to access and reuse corporate information for competitive advantage, ultimately changing business outcomes.
Reg Reader Research: SaaS based Email and Office Productivity Tools
Read this Reg reader report which provides advice and guidance for SMBs towards the use of SaaS based email and Office productivity tools.