How severe is CVE-1999-0016?

No CVSS score has been assigned to CVE-1999-0016 yet. Review the advisory details and affected package list to assess your exposure.

Which products are affected by CVE-1999-0016?

CVE-1999-0016 affects the following products: cisco ios, gnu inet, hp hp-ux, microsoft windows 95, microsoft windows nt, microsoft winsock, netbsd netbsd, sun sunos.

How do I patch CVE-1999-0016?

No patch has shipped for CVE-1999-0016 yet — track the cisco ios advisory for a fixed release and apply the workarounds below in the meantime.

How do I detect CVE-1999-0016 across my infrastructure?

Inventory every cisco ios deployment and check each version against the affected-products list above.

How do I mitigate CVE-1999-0016 if there is no patch (or I can't update yet)?

Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service. Alongside that, restrict the management interface to trusted networks and apply the vendor's recommended configuration mitigations.

Is CVE-1999-0016 actively exploited in the wild?

Yes. There are 5 known exploit references for CVE-1999-0016, including 5 documented proof-of-concept exploits on Exploit-DB. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-1999-0016?

CVE-1999-0016 has an EPSS (Exploit Prediction Scoring System) score of 96.4%, placing it in the 100th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. A score above 50% indicates significantly elevated exploitation risk — immediate patching is strongly recommended.

Which products and versions are affected by CVE-1999-0016?

CVE-1999-0016 affects cisco ios (1 version, e.g. 7000); gnu inet (1 version, e.g. 5.01); hp hp-ux (14 versions, e.g. 9.00, 9.01, 9.03…); microsoft windows 95, and 4 more product(s). Check the affected-products list on this page against your deployed version to confirm exposure.

When was CVE-1999-0016 published, and has it been updated?

CVE-1999-0016 was published on December 1, 1997 and was last updated on June 16, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

Not in CISA KEV

CVE-1999-0016 — IOS

CVE-1999-0016 is a security vulnerability in cisco ios. 5 public exploit references exist, so weaponization risk is real. No vendor fix is recorded yet; mitigation options are listed below.

Land IP denial of service.

Published

Dec 1, 1997

Updated

Jun 16, 2026

Affected

8 products

Patched

See advisory

Exploits

5 known

Exploitation data as of Oct 28, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

96.4%probability of exploitation in next 30 days

Very High Risk+0.69%

Lower risk than most CVEs100th percentile — riskier than 100% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Description

Land IP denial of service.

Affected Products

8 products · 23 configurations

ioscisco

1 version

7000

Application

inetgnu

1 version

5.01

hp-uxhp

14 versions

9.009.019.039.049.059.0710.0010.0110.1010.1610.2010.24

windows 95microsoft

all

windows ntmicrosoft

1 version

4.0

Application

winsockmicrosoft

1 version

2.0

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

EDB-20810dosmultiple✓ Verified

FreeBSD 2.x / HP-UX 9/10/11 / Kernel 2.0.3 / Windows NT 4.0/Server 2003 / NetBSD 1 - 'land.c' loopback Denial of Service (1)

by m3lt · Nov 20, 1997

Exploit-DB Source

EDB-20812doswindows✓ Verified

FreeBSD 2.x / HP-UX 9/10/11 / Kernel 2.0.3 / Windows NT 4.0/Server 2003 / NetBSD 1 - 'land.c' loopback Denial of Service (3)

by m3lt · Nov 20, 1997

Exploit-DB Source

EDB-20814doswindows✓ Verified

FreeBSD 2.x / HP-UX 9/10/11 / Kernel 2.0.3 / Windows NT 4.0/Server 2003 / NetBSD 1 - 'land.c' loopback Denial of Service (5)

by Dejan Levaja · Nov 20, 1997

Exploit-DB Source

EDB-20811dosmultiple✓ Verified

FreeBSD 2.x / HP-UX 9/10/11 / Kernel 2.0.3 / Windows NT 4.0/Server 2003 / NetBSD 1 - 'land.c' loopback Denial of Service (2)

by Konrad Malewski · Nov 20, 1997

Exploit-DB Source

EDB-20813dosmultiple✓ Verified

FreeBSD 2.x / HP-UX 9/10/11 / Kernel 2.0.3 / Windows NT 4.0/Server 2003 / NetBSD 1 - 'land.c' loopback Denial of Service (4)

by MondoMan · Nov 20, 1997

Exploit-DB Source

Detection & mitigation playbook

Vendor / appliance

Detect
Inventory every cisco ios deployment and check each version against the affected-products list above.
Remediation status
No patch has shipped for CVE-1999-0016 yet — track the cisco ios advisory for a fixed release and apply the workarounds below in the meantime.
Mitigate without a patch
Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service. Alongside that, restrict the management interface to trusted networks and apply the vendor's recommended configuration mitigations.

Frequently Asked Questions

Land IP denial of service.

O3 Security · Runtime Protection

Is CVE-1999-0016 being exploited in your environment?

Detect and block the exploit chain at execution, on systems you cannot patch yet.

Protect my workloads How runtime protection works

CVE-1999-0016 — IOS

EPSS Exploitation Probability

Description

Affected Products

Detection & mitigation playbook

Detect

Remediation status

Mitigate without a patch

Frequently Asked Questions

Is CVE-1999-0016 being exploited in your environment?