glibc getaddrinfo() stack overflow

2013.04.03

Credit: Marcus Meissner

Risk: Low

Local: Yes

Remote: Yes

CVE: CVE-2013-1914

CWE: N/A

CVSS Base Score: 5/10

Impact Subscore: 2.9/10

Exploitability Subscore: 10/10

Exploit range: Remote

Attack complexity: Low

Authentication: No required

Confidentiality impact: None

Integrity impact: None

Availability impact: Partial

A customer reported a glibc crash, which turned out to be a stack overflow in
getaddrinfo().

getaddrinfo() uses:
        struct sort_result results[nresults];
with nresults controlled by the nameservice chain (DNS or /etc/hosts).

This will be visible mostly on threaded applications with smaller stacksizes,
or operating near out of stack.

Reproducer I tried:
        $ for i in `seq 1 10000000`; do echo "ff00::$i a1" >>/etc/hosts; done
        $ ulimit -s 1024
        $ telnet a1
        Segmentation fault
        (clean out /etc/hosts again )


I am not sure you can usually push this amount of addresses via DNS for all
setups.

Andreas is currently pushing the patch to glibc GIT.

Reference:
https://bugzilla.novell.com/show_bug.cgi?id=813121

Ciao, Marcus

References:

https://bugzilla.novell.com/show_bug.cgi?id=813121

http://seclists.org/oss-sec/2013/q2/8

See this note in RAW Version

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glibc getaddrinfo() stack overflow

References:

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