CVE-2001-0688: Broker FTP Server 5.9.5.0 allows a remote attacker to cause a denial of service by repeatedly issuing an inval

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MEDIUM 5.0DOWNGRADE

CVE-2001-0688 is a medium-severity flaw (CVSS 5.0) affecting broker ftp server. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Broker FTP Server 5.9.5.0 allows a remote attacker to cause a denial of service by repeatedly issuing an invalid CD or CWD ("CD . .") command.

Why this priority

EPSS top 8%: very likely to be exploited
Public exploit reference

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	5.0 (Medium)
EPSS exploit chance	5.1% (top 8%)
CISA exploited list	No
Published	2001-09-20
Last modified	2026-06-16

Publisher (CNA): MITRE · Vendor: transsoft

Last updated 2026-06-16 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2001-09-20 04:00 UTCPublished CVE record published
2026-06-16 21:54 UTCUpdated Record last modified

transsoft broker ftp server DOWNGRADE

Affected: 3.0_build_1 · 4.0 · 4.7.5.0 · 5.0 · 5.1 · 5.7 · 5.9.5.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 3.0_build_1

1. Check installed version

apt-cache policy broker-ftp-server || rpm -q broker-ftp-server || broker-ftp-server --version

2. No fixed release: DOWNGRADE to a release before 3.0_build_1 (Debian / Ubuntu)

apt-cache madison broker-ftp-server sudo apt install broker-ftp-server=<VERSION_BEFORE_3.0_build_1> sudo apt-mark hold broker-ftp-server

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list broker-ftp-server sudo dnf downgrade broker-ftp-server-<VERSION_BEFORE_3.0_build_1> sudo dnf versionlock add broker-ftp-server

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

Exploit-DB: TransSoft Broker FTP Server 3.0/4.0/4.7/5.x - CWD Buffer Overflow

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2001-0688?

broker ftp server: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2001-0688 being exploited?

CVE-2001-0688 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2001-0688 affect?

CVE-2001-0688 affects broker ftp server. Severity is medium (CVSS 5.0). Broker FTP Server 5.9.5.0 allows a remote attacker to cause a denial of service by repeatedly issuing an invalid CD or CWD ("CD . .") command.

How urgent is CVE-2001-0688?

Priority 46/100. EPSS top 8%: very likely to be exploited; Public exploit reference

Related CVEs

CVE-2004-0296 MEDIUM 5.0 DOWNGRADE TsFtpSrv.exe in Broker FTP 6.1.0.0 allows remote attackers to cause a TsFtpSrv.exe to exit with an exception b
CVE-2004-0295 MEDIUM 5.0 DOWNGRADE TsFtpSrv.exe in Broker FTP 6.1.0.0 allows remote attackers to cause a denial of service (CPU consumption) via
CVE-2002-0405 HIGH 10.0 DOWNGRADE Buffer overflow in Transsoft Broker FTP Server 5.0 evaluation allows remote attackers to cause a denial of ser
CVE-2001-1042 HIGH 7.5 DOWNGRADE Transsoft Broker 5.9.5.0 allows remote attackers to read arbitrary files and directories by uploading a .lnk (
CVE-2001-0687 MEDIUM 5.0 UPGRADE Broker FTP server 5.9.5 for Windows NT and 9x allows a remote attacker to retrieve privileged web server syste

References

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