# CVE-1999-0101: IBM AIX and Sun Solaris buffer overflow in gethostbyname

Source: https://junglewise.ai/threats/cve-1999-0101-ibm-aix-and-sun-solaris-buffer-overflow-in-gethostbyname  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 1996-12-10. Updated: 2026-05-10  
License: CC BY 4.0 with a link back

CVE-1999-0101 · Severity: critical · CVSS 10 · Published 1996-12-10

A critical vulnerability exists in the core networking libraries of AIX and Solaris operating systems. These systems use a specific function to translate computer names into IP addresses; by providing a specially crafted, malicious name via DNS, an attacker can take complete control of the server. This allows for unauthorized access to sensitive data, system-wide outages, or the installation of malicious software with the highest possible privileges (root).

Technologies: [IBM Aix](https://junglewise.ai/threats/technologies/aix). Vendors: [IBM](https://junglewise.ai/threats/vendors/ibm).

## Quick answers

**Is CVE-1999-0101 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-1999-0101 being exploited in the wild.

**How severe is CVE-1999-0101?** Critical severity, with a CVSS score of 10, published 10 December 1996.

**Which products and versions are affected?** IBM AIX; Sun Microsystems Solaris.

**Is there a fix for CVE-1999-0101?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-1999-0101 attacked?** It is attacked over the network, in an operating system.

**Am I affected by CVE-1999-0101?** Check whether you run IBM Aix. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

A classic buffer overflow vulnerability exists within the 'gethostbyname' library function used by AIX and Solaris for DNS resolution. The flaw is triggered when the function processes a DNS response containing an oversized or corrupt host name that exceeds the allocated buffer size. Because this library is utilized by numerous privileged system services and applications, a remote, unauthenticated attacker can exploit this overflow to overwrite memory and execute arbitrary code. Successful exploitation typically results in a full compromise of the affected system with root-level privileges. The attack vector is the network, specifically targeting any service that performs name resolution on untrusted input.

## Affected products

- IBM AIX
- Sun Microsystems Solaris

## Timeline

- 1996-12-10: disclosed

## References

- [http://ciac.llnl.gov/ciac/bulletins/h-13.shtml](http://ciac.llnl.gov/ciac/bulletins/h-13.shtml)

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