CVE-1999-0377
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedProcess table attack in Unix systems allows a remote attacker to perform a denial of service by filling a machine's process tables through multiple connections to network services.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · moderate confidenceA remote denial of service vulnerability in Unix systems where an attacker exhausts the system's process table by opening multiple connections to various network services. Once the process table is full, legitimate users cannot establish new connections to services.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE dataall versionsCVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Authentication
- None
- Confidentiality
- None
- Integrity
- None
- Availability
- Partial
AV:N/AC:L/Au:N/C:N/I:N/A:P
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Check system process limitsRun `ulimit -u` to view the maximum number of processes allowed per user. Run `cat /etc/security/limits.conf` (or equivalent) to check if process limits are configured in PAM or system limits.Affected if If the limit is set very high or is unlimited (unrestricted), the system is vulnerable to process table exhaustion.
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Review active network connectionsRun `netstat -an | grep ESTABLISHED | wc -l` or `ss -tan | grep ESTABLISHED | wc -l` to count current established connections. Run `netstat -an | wc -l` for total socket count.Affected if If connection counts are not monitored or throttled, an attacker can easily reach system limits.
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Check for per-source IP connection limitsInspect firewall configuration: run `iptables -L -n -v` or `ipfw list` or equivalent for your Unix variant. Look for rules with connection limit (--connlimit) or rate limit flags.Affected if If no firewall rules exist to limit connections per source IP address, the system is vulnerable.
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Verify service-level rate limitingCheck network service configurations (e.g., inetd.conf, xinetd.conf, or systemd service files) for built-in connection rate controls or tcp wrappers configuration.Affected if If network services accept unlimited connections without rate limiting, the process table can be exhausted.
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Check for connection tracking limitsRun `sysctl net.netfilter.nf_conntrack_max` or equivalent to check the connection tracking table size. Run `sysctl net.netfilter.nf_conntrack_count` to see current usage.Affected if If connection tracking limits are unset or set very high with no monitoring, the system can be overwhelmed.
A system is affected if it lacks process/connection limits at the kernel, firewall, or service level, allowing an attacker to exhaust the process table through excessive connections.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataImplement connection rate limiting on network services, configure per-user or per-source IP connection limits, and apply firewall rules to restrict the number of concurrent connections from a single source. For legacy systems, consider upgrading to modern Unix variants with better process limit controls.
- Consultation2.0 h
- Implementation3.0 h
- Testing2.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-1999-0377 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-1999-0377 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Version or environment caveats, and links to real fixes
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