HOMEVULNERABILITIESCVE-2003-0740
MEDIUMPOC

CVE-2003-0740

NVD-CWE-OtherPublished: October 20, 2003· Updated: Jun 16, 2026

4.6
CVSS v3.1

Official Description

Stunnel 4.00, and 3.24 and earlier, leaks a privileged file descriptor returned by listen(), which allows local users to hijack the Stunnel server.

NVD Source

Technical Analysis

CVE-2003-0740 requires local access, meaning attackers must already have a foothold on the target system.

Exploitation requires some privileges, which limits the exposure to scenarios where an attacker has already gained initial access.

A proof-of-concept (PoC) exploit exists for CVE-2003-0740. While not yet confirmed in active campaigns, the availability of PoC code increases exploitation risk substantially.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorLocal
Attack ComplexityLow
Privileges Req.
User Interaction
Scope
Impact
ConfidentialityP
IntegrityP
AvailabilityP
AV:L/AC:L/Au:N/C:P/I:P/A:P

Affected Vendors & Products

stunnel1 product(s)
stunnel
Source: NVD CPE · 23 total CPE entries

Exploit & PoC Resources

POC AVAILABLEProof-of-concept code exists
External links open in a new tab. Always verify in a controlled environment before use.

All References (8)

Quick Facts

CVE IDCVE-2003-0740
CVSS Score4.6 / 10
SeverityMEDIUM
CISA KEVNo
ExploitPOC
Affected1 vendor(s)
PublishedOct 20, 2003

Related CVEs (NVD-CWE-Other)

Recommended Actions

  • Apply vendor patches immediately
  • Monitor CVE-2003-0740 in threat intel feeds
  • Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.