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possible attempt to exploit buffer overflow?

Nov  6 01:24:44 mail nscd[289]: [ID 461630 user.crit] gethostans: possible attempt to exploit buffer overflow while looking up linux.somesite.com.my

OS: Solaris 9

The above is the warning message I found in /var/adm/messages few days back. And there's only one of it.

May I know exactly what is this? I was told that the malicious attempt (if there's one) could hang the system. Is there any patches or setting I can set to prevent such attempt to occur?

The system is still running fine but prevention is better than cure.

Thanks.
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shawnk
Asked:
shawnk
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2 Solutions
 
wesly_chenCommented:
Hi,

   nscd is Name Service Cache Daemon. It caches for name services such as NIS, DNS, LDAP...
You can go to the URL to download the latest patch for nscd.
http://sunsolve.sun.com/search/document.do?assetkey=1-21-110710-02-1&searchclause=nscd%20solaris%209

The instruction to install is at the bottom of that page:
# patchadd /var/spool/patch/104945-02

Regards,

Wesly
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yuzhCommented:
Please apply the Solaris Recommended Patch Clusters and add the followings to
 /etc/system file:

       * Disable the ability to execute code from the stack
       * This will actively prevent many buffer overflows
       set noexec_user_stack=1

       * This will report buffer overflows
       set noexec_user_stack_log=1

You need to reboot the box after the change.
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shawnkAuthor Commented:
Hi guys,
Thanks for the info.
Would appreciate if the admin can give yuzh's answer as "accepted answer" as well.
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shawnkAuthor Commented:
Hi wesly,
Oops, the patch link you gave me above is for Solaris 8 but I'm using Solaris 9.

Yuzh,
Would appreciate if you have the specific patch instead of the cluster patch... wouldn't want to risk having new problems if you know what I mean...

I looked through the Sol 9 report but there isn't any nscd patch included in there. Maybe I'm just looking at the wrong keyword.
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wesly_chenCommented:
Hi,

   There is no patch directly for nscd on Solaris 9. However, there is one which might related.
http://sunsolve.sun.com/search/document.do?assetkey=1-21-114713-02-1&searchclause=sunOS%205.9%20nscd

  You can make a request to ask to split the points.

Wesly
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shawnkAuthor Commented:
I guess I will start resolving this issue by making the setting in /etc/system like what Yuzh has suggested and see how it goes.

The server is actually a mail server. Not sure why the nscd daemon (in my case its purpose it's probably for hosts lookups caching purpose?) is causing this buffer overflow warning message.

Anyway thanks guys.
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