NetBSD/OpenBSD FTPD replydirname off-by-one

CVSS Meta Temp Score
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CTI Interest Score
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9.0$0-$5k0.00

Summaryinfo

A vulnerability classified as critical has been found in NetBSD and OpenBSD. This vulnerability affects the function replydirname of the component FTPD. This manipulation causes off-by-one. This vulnerability appears as CVE-2001-0053. In addition, an exploit is available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability has been found in NetBSD and OpenBSD (Operating System) (version now known) and classified as critical. Affected by this vulnerability is the function replydirname of the component FTPD. The manipulation with an unknown input leads to a off-by-one vulnerability. The CWE definition for the vulnerability is CWE-193. A product calculates or uses an incorrect maximum or minimum value that is 1 more, or 1 less, than the correct value. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

One-byte buffer overflow in replydirname function in BSD-based ftpd allows remote attackers to gain root privileges.

The weakness was presented 12/18/2000 (Website). The advisory is shared at openbsd.org. This vulnerability is known as CVE-2001-0053. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Technical details and also a public exploit are known.

It is possible to download the exploit at exploit-db.com. It is declared as proof-of-concept. The vulnerability scanner Nessus provides a plugin with the ID 11371 (BSD ftpd Single Byte Buffer Overflow), which helps to determine the existence of the flaw in a target environment. It is assigned to the family FTP and running in the context r. The commercial vulnerability scanner Qualys is able to test this issue with plugin 27099 (BSD FTPd Single Byte Buffer Overflow Vulnerability).

Upgrading eliminates this vulnerability. Attack attempts may be identified with Snort ID 339. Furthermore it is possible to detect and prevent this kind of attack with TippingPoint and the filter 669.

The vulnerability is also documented in the databases at X-Force (5776), Exploit-DB (234), Tenable (11371), SecurityFocus (BID 2124†) and OSVDB (1693†). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Type

Name

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 10.0
VulDB Meta Temp Score: 9.0

VulDB Base Score: 10.0
VulDB Temp Score: 9.0
VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍

Exploitinginfo

Class: Off-by-one
CWE: CWE-193 / CWE-189
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Access: Public
Status: Proof-of-Concept
Download: 🔍

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Nessus ID: 11371
Nessus Name: BSD ftpd Single Byte Buffer Overflow
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

OpenVAS ID: 11371
OpenVAS Name: BSD ftpd Single Byte Buffer Overflow
OpenVAS File: 🔍
OpenVAS Family: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

Exploit-DB: 🔍

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍
Snort ID: 339

Suricata ID: 2100339
Suricata Class: 🔍
Suricata Message: 🔍

TippingPoint: 🔍

McAfee IPS: 🔍
McAfee IPS Version: 🔍

SourceFire IPS: 🔍
Fortigate IPS: 🔍

Timelineinfo

12/18/2000 🔍
12/18/2000 +0 days 🔍
12/20/2000 +2 days 🔍
02/12/2001 +54 days 🔍
02/21/2003 +739 days 🔍
03/13/2003 +19 days 🔍
06/18/2003 +97 days 🔍
07/03/2014 +4033 days 🔍
10/10/2025 +4117 days 🔍

Sourcesinfo

Advisory: openbsd.org
Status: Confirmed

CVE: CVE-2001-0053 (🔍)
GCVE (CVE): GCVE-0-2001-0053
GCVE (VulDB): GCVE-100-16393
X-Force: 5776 - BSD ftpd replydirname() function buffer overflow
SecurityFocus: 2124 - BSD ftpd Single Byte Buffer Overflow Vulnerability
OSVDB: 1693 - BSD ftpd Single Byte Overflow
Vulnerability Center: 1220 - Buffer Overflow in BSD-Based FTP Daemons Allows Arbitrary Code Execution with Root Privilege, High

scip Labs: https://www.scip.ch/en/?labs.20161013

Entryinfo

Created: 07/03/2014 10:39
Updated: 10/10/2025 08:08
Changes: 07/03/2014 10:39 (81), 05/10/2019 07:10 (5), 06/30/2024 00:06 (16), 10/10/2025 08:08 (5)
Complete: 🔍
Cache ID: 216::103

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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