Cisco Cisco IOS Software Release 12.2(15)ZN 릴리즈 노트

Caveats describe unexpected behavior or defects in the Cisco IOS software releases. Severity 1 caveats 
are the most serious caveats, severity 2 caveats are less serious, and severity 3 caveats are the 
least serious of these three severity levels.

Caveats in Cisco IOS Release 12.2(15)T are also in Release 12.2(15)ZN1. For information on caveats in 
Cisco IOS Release 12.2(15)T, refer to the 

 document. For 

information on caveats in Cisco IOS Release 12.2, refer to the 

 

document. These documents list severity 1 and 2 caveats; the documents are located on Cisco.com and 
the Documentation CD.

If you have an account with Cisco.com, you can also use the Bug Toolkit to find select caveats of any 
severity. To reach the Bug Toolkit, log in to Cisco.com and click Service & Support: Technical 
Assistance Center: Tool Index: Bug Toolkit. Another option is to go to 

.

The following sections list the resolved caveats for the Cisco IOS Release 12.2(15)ZN.

CSCdu53656

A Cisco device running IOS and enabled for the Border Gateway Protocol (BGP) is vulnerable to a 
Denial of Service (DOS) attack from a malformed BGP packet. The BGP protocol is not enabled by 
default, and must be configured in order to accept traffic from an explicitly defined peer. Unless the 
malicious traffic appears to be sourced from a configured, trusted peer, it would be difficult to inject 
a malformed packet. BGP MD5 is a valid workaround for this problem.

Cisco has made free software available to address this problem. For more details, please refer to this 
advisory, available at 

.

CSCdv59309

Two vulnerabilities exist in the virtual private dial-up network (VPDN) solution when Point-to-Point 
Tunneling Protocol (PPTP) is used in certain Cisco IOS releases prior to 12.3. PPTP is only one of 
the supported tunneling protocols used to tunnel PPP frames within the VPDN solution.

The first vulnerability is a memory leak that occurs as a result of PPTP session termination. The 
second vulnerability may consume all interface descriptor blocks on the affected device because 
those devices will not reuse virtual access interfaces. If these vulnerabilities are repeatedly 
exploited, the memory and/or interface resources of the attacked device may be depleted.

Cisco has made free software available to address these vulnerabilities for affected customers.

There are no workarounds available to mitigate the effects of these vulnerabilities.

This advisory is posted at

CSCea22552

GRE implementation of Cisco IOS is compliant with RFC2784 and RFC2890 and backward 
compatible with RFC1701. 

As an RFC compliancy this DDTS adds the check for bits 4-5 (0 being the most significant) of GRE 
header. 

This issue does not cause any problem for router operation.