cbcvebase.
CVE-2018-19052
published 2018-11-07

CVE-2018-19052: An issue was discovered in mod_alias_physical_handler in mod_alias.c in lighttpd before 1.4.50. There is potential ../ path traversal of a single directory…

PriorityP347high7.5CVSS 3.1
AVNACLPRNUINSUCHINAN
EPSS
14.08%
96.2th percentile
An issue was discovered in mod_alias_physical_handler in mod_alias.c in lighttpd before 1.4.50. There is potential ../ path traversal of a single directory above an alias target, with a specific mod_alias configuration where the matched alias lacks a trailing '/' character, but the alias target filesystem path does have a trailing '/' character.

Affected

15 ranges
VendorProductVersion rangeFixed in
debiandebian_linux
debianlighttpd< lighttpd 1.4.52-1 (bookworm)lighttpd 1.4.52-1 (bookworm)
lighttpdlighttpd< 1.4.501.4.50
lighttpdlighttpd>= 0 < 1.4.52-11.4.52-1
lighttpdlighttpd>= 0 < 1.4.52-11.4.52-1
lighttpdlighttpd>= 0 < 1.4.52-11.4.52-1
lighttpdlighttpd>= 0 < 1.4.52-11.4.52-1
lighttpdlighttpd>= 0 < 1.4.33-1+nmu2ubuntu2.1+esm11.4.33-1+nmu2ubuntu2.1+esm1
lighttpdlighttpd>= 0 < 1.4.35-4ubuntu2.1+esm11.4.35-4ubuntu2.1+esm1
lighttpdlighttpd>= 0 < 1.4.45-1ubuntu3.18.04.1+esm11.4.45-1ubuntu3.18.04.1+esm1
opensusebackports_sle
opensuseleap
opensuseleap
susesuse_linux_enterprise_server
susesuse_linux_enterprise_server

Detection & IOCsextracted from sources · hover to see the quote

  • Path traversal attack pattern: requests containing '../' one directory above an alias target should be flagged when mod_alias is configured without a trailing '/' on the alias match but with a trailing '/' on the target filesystem path
  • Vulnerable component is mod_alias_physical_handler in mod_alias.c within lighttpd; focus detection on lighttpd instances running versions before 1.4.50
  • The attack vector is network-based (remote attacker); monitor HTTP requests to lighttpd servers for directory traversal sequences targeting paths served via mod_alias
  • ·Vulnerability is only exploitable under a specific mod_alias configuration: the alias match string must lack a trailing '/' while the alias target filesystem path must have a trailing '/' — deployments not matching this pattern are not affected
  • ·Traversal is limited to a single directory level above the alias target, not arbitrary depth

CVSS provenance

nvdv3.17.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
nvdv2.05.0MEDIUMAV:N/AC:L/Au:N/C:P/I:N/A:N
osv7.5HIGH
vendor_debian7.5HIGH
vendor_ubuntu7.5HIGH
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