UpHeron
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Servers and applications

CVE-2001-1556

The log files in Apache web server contain information directly supplied by clients and does not filter or quote control characters, which could allow remote attackers to hide HTTP requests and spoof source IP addresses when logs are viewed with UNIX programs such as cat, tail, and grep.

Severity
Medium 5.0
Published
31 Dec 2001
Last changed
16 Jun 2026
Added to UpHeron
17 Oct 2026
Fixed in
1.3.31, 2.0.49
Exploit chance
3.6% in the next 30 daysHigher than 89% of CVEs. EPSS by FIRST, 12 Nov 2026
Weakness
Sensitive information in log files (CWE-532)
Attack
Over the network · No login needed
Attacker can
Change some data
CVSS vector
AV:N/AC:L/Au:N/C:N/I:P/A:N
Sources
NVD

Affected software

SoftwareAffected versions
Apache HTTP ServerServers and applications · cpe:a:apache:http_server
  • From 1.3.0 before 1.3.31
  • From 2.0.0 before 2.0.49

References

  • NVD https://nvd.nist.gov/vuln/detail/CVE-2001-1556
  • CVE.org https://www.cve.org/CVERecord?id=CVE-2001-1556