Buffer overflow in ntpd ntp daemon 4.0.99k and earlier (aka xntpd and xntp3) allows remote attackers to cause a denial of service and possib
Buffer overflow in ntpd ntp daemon 4.0.99k and earlier (aka xntpd and xntp3) allows remote attackers to cause a denial of service and possibly execute arbitrary commands via a long readvar argument.
- Published
- Jun 18, 2001
- Updated
- Jun 16, 2026
- EPSS
- 91.7% · 100th percentile
- CWE
- —
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Report tools
Action score
68
This week
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- CVSS
- 40 / 40 · 10.0 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 28 / 30 · 91.7%
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for the hundreds of thousands of vulnerabilities in the database; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpAffected systems
| Vendor | Product | CPE |
|---|---|---|
| dave mills | ntpd | cpe:2.3:a:dave_mills:ntpd |
| dave mills | xntp3 | cpe:2.3:a:dave_mills:xntp3 |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- dave mills ntpdup to 4.0.99k inclusive
- dave mills ntpd4.0.99
- dave mills ntpd4.0.99a
- dave mills ntpd4.0.99b
- dave mills ntpd4.0.99c
- dave mills ntpd4.0.99d
- dave mills ntpd4.0.99e
- dave mills ntpd4.0.99f
- dave mills ntpd4.0.99g
- dave mills ntpd4.0.99h
- dave mills ntpd4.0.99i
- dave mills ntpd4.0.99j
- dave mills xntp35.93
- dave mills xntp35.93a
- dave mills xntp35.93b
- dave mills xntp35.93c
- dave mills xntp35.93d
- dave mills xntp35.93e
Same product
dave mills: all recordsOther highest-scoring records for the same primary product.
- CVE-2005-2496The xntpd ntp (ntpd) daemon before 4.2.0b, when run with the -u option and using a string to specify the group, uses the group ID of the use18Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
No fix version is recorded for this entry. Check the references for vendor advisories.
Exploit status
Weaponized
A ready exploit tool or active in-the-wild use is known for this vulnerability. This should be your top priority.
Evidence
- Metasploit module ×1
- Exploit-DB entry ×3
Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.
| Source | Kind | Date |
|---|---|---|
| Exploit-DB entry | remote | 2010-08-25 |
| Exploit-DB entry | remote | 2001-04-04 |
| Exploit-DB entry | remote | 2001-04-04 |
| Metasploit module | exploit/multi/ntp/ntp_overflowNTP Daemon readvar Buffer Overflowexploit | 2001-04-04 |
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
- First PoC-75 d
- Metasploit-75 d
- Published
- TodayOct 9, 2026+9245 d
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- C · data can be read
- Integrity
- C · data or configuration can be modified
- Availability
- C · the service can be disrupted
- Attack complexity
- Low
- Confidentiality impact
- C
- Integrity impact
- C
- Availability impact
- C
Weakness class (CWE)
—
CVSS vector
AV:N/AC:L/Au:N/C:C/I:C/A:C
nvd-primary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Change log
No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.
References
- ftp://ftp.FreeBSD.org/pub/FreeBSD/CERT/advisories/FreeBSD-SA-01:31.ntpd.asc
- ftp://ftp.netbsd.org/pub/NetBSD/misc/security/advisories/NetBSD-SA2001-004.txt.asc
- ftp://ftp.sco.com/SSE/sse073.ltr
- ftp://ftp.sco.com/SSE/sse074.ltr
- archives.neohapsis.com/archives/bugtraq/2001-04/0127.html
- archives.neohapsis.com/archives/bugtraq/2001-04/0225.html
- archives.neohapsis.com/archives/bugtraq/2001-04/0314.html
- distro.conectiva.com.br/atualizacoes/?id=a&anuncio=000392
- lists.suse.com/archives/suse-security-announce/2001-Apr/0000.html
- marc.info/?l=bugtraq&m=98642418618512&w=2
- marc.info/?l=bugtraq&m=98654963328381&w=2
- marc.info/?l=bugtraq&m=98659782815613&w=2
- marc.info/?l=bugtraq&m=98679815917014&w=2
- marc.info/?l=bugtraq&m=98683952401753&w=2
- marc.info/?l=bugtraq&m=98684202610470&w=2
- marc.info/?l=bugtraq&m=98684532921941&w=2
- www.calderasystems.com/support/security/advisories/CSSA-2001-013.0.txt
- www.linux-mandrake.com/en/security/2001/MDKSA-2001-036.php3
- www.osvdb.org/805
- www.redhat.com/support/errata/RHSA-2001-045.html
Vendor advisories and official records. Exploit/PoC links are deliberately left out.