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Update Protection against LibSPF2 DNS TXT Records Parsing Buffer Overflow Vulnerability

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Check Point Reference: CPAI-2008-230
Date Published:
Severity:
Last Updated:
Source: FrSIRT/ADV-2008-2896
Industry Reference(s): CVE-2008-2469
Protection Provided by: VPN-1
  • NGX R65
  • NGX R62
  • NGX R61
  • NGX R60
VSX
  • NGX R65
InterSpect
  • NGX
IPS-1
  • IPS-1
  • IPS-1 NGX R65
Who is Vulnerable?
SPF Library Project libSPF2 prior to 1.2.8
Vulnerability Description
A buffer overflow vulnerability was reported in LibSPF2, a widely deployed implementation of Sender Policy Framework (SPF). LibSPF2 contains a buffer overflow vulnerability in the code that parses DNS TXT records. An attacker who runs a malicious DNS server can exploit this vulnerability by sending a message with overly long TXT records to the target system. Successful exploitation could allow for execution of arbitrary code.  
Vulnerability Details
This issue is caused by a buffer overflow error in the "SPF_dns_resolv_lookup()" [spf_dns_resolv.c] function when processing overly long DNS TXT records. Successful attack could result in remote code execution or application termination.

Protection Overview
By enabling this protection, SmartDefense will detect and block malformed DNS TXT resource records.

In order for the protection to be activated, update your VPN-1/InterSpect product to the latest SmartDefense update. For information on how to update SmartDefense, go to SBP-2006-05, Protection tab and select the version of your choice.

IPS-1 users are already protected against this vulnerability. The protection will detect and block certain malformed DNS responses.  No update required for IPS-1.

To configure the defense, select your product from the list below and follow the related protection steps.

VPN-1 NGX R65 & R62

How Can I Protect My Network?
1. In the SmartDefense tab, click Application Intelligence > DNS > Malformed Resource Records > DNS TXT Record Parsing Buffer Overflow.
2. In the configuration pane, under Settings > Mode, check Active.
3. Install policy on all modules.

How Do I Know if My Network is Under Attack?
SmartView Tracker will log the following entries:

Attack Name: DNS Enforcement Violation
Attack Information: DNS TXT record parsing buffer overflow

VPN-1 NGX R61 & R60

How Can I Protect My Network?
1. In the Application Intelligence tree, click DNS > Malformed Resource Records.
2. Select the following:

DNS TXT Record Parsing Buffer Overflow

3. Install security policy on all modules.

How Do I Know if My Network is Under Attack?
SmartView Tracker will log the following entries:

Attack Name: DNS Enforcement Violation
Attack Information: DNS TXT record parsing buffer overflow

VPN-1 VSX NGX R65

How Can I Protect My Network?
1. In the SmartDefense tab, click Application Intelligence > DNS > Malformed Resource Records > DNS TXT Record Parsing Buffer Overflow.
2. In the configuration pane, under Settings > Mode, check Active.
3. Install policy on all modules.

How Do I Know if My Network is Under Attack?
SmartView Tracker will log the following entries:

Attack Name: DNS Enforcement Violation
Attack Information: DNS TXT record parsing buffer overflow

InterSpect NGX

How Can I Protect My Network?
1. In the left pane select Profiles > Default Protection and select the SmartDefense page of the profile.
2. In the SmartDefense tree, click DNS > Malformed Resource Records.
3. Select the following:

DNS TXT Record Parsing Buffer Overflow

4. Install security policy on all modules.

How Do I Know if My Network is Under Attack?
SmartView Tracker will log the following entries:

Attack Name: DNS Enforcement Violation
Attack Information: DNS TXT record parsing buffer overflow

IPS-1 & IPS-1 NGX R65

How Can I Protect My Network?
1. In the IPS-1 Policy Manager, click on the Protection tab.
2. In the Protection tree, click Network Security > DNS, and select the Labels protection group
3. Click ms06_041_alert (IPS-1 NGX R65 only).
4. In the configuration pane, under Settings, check Active.
5. Click on Install Policy.

How Do I Know if My Network is Under Attack?
Upon attack, the following entries will be logged:

Alert Name: DNS Names and Labels Alerts
Description: ms06_041_alert