cbcvebase.
CVE-2020-1956
published 2020-05-22

CVE-2020-1956: Apache Kylin 2.3.0, and releases up to 2.6.5 and 3.0.1 has some restful apis which will concatenate os command with the user input string, a user is likely to…

PriorityP193high8.8CVSS 3.1
AVNACLPRLUINSUCHIHAH
KEVITWEXPLOIT
CISA Known Exploited Vulnerabilitydue 2022-04-15
Exploited in the wild
EPSS
97.34%
99.9th percentile
Apache Kylin 2.3.0, and releases up to 2.6.5 and 3.0.1 has some restful apis which will concatenate os command with the user input string, a user is likely to be able to execute any os command without any protection or validation.

Affected

11 ranges
VendorProductVersion rangeFixed in
apachekylin
apachekylin
apachekylin
apachekylin
apachekylin
apachekylin
apachekylin
apachekylin>= 2.3.0 < 3.1.03.1.0
apachekylin2.3.0 – 2.3.2
apachekylin2.5.0 – 2.5.2
apachekylin2.6.0 – 2.6.5

Detection & IOCsextracted from sources · hover to see the quote

url/kylin/api/user/authentication
url/kylin/api/cubes/kylin_streaming_cube/%2031%60curl%20{{interactsh-url}}%60/migrate
  • Exploit targets the /kylin/api/cubes/{cube_name}/migrate REST endpoint by injecting OS commands via URL-encoded backtick shell metacharacters in the cube name parameter (e.g., %60curl%20<host>%60).
  • Exploitation is preceded by an authentication step against /kylin/api/user/authentication using HTTP Basic auth; monitor for sequential POST requests to both endpoints from the same source.
  • Out-of-band callback via curl is used to confirm RCE; detect by monitoring for outbound HTTP requests with 'User-Agent: curl' originating from the Kylin server process.
  • The injected command is embedded in the URL path using URL-encoded backtick characters (%60) as shell command substitution delimiters; look for %60 or backtick characters in HTTP request paths targeting /kylin/api/cubes/.
  • Apache Kylin instances can be fingerprinted via favicon hash -186961397 on Shodan or FOFA for attack surface identification.
  • ·The exploit requires valid (low-privileged) credentials to first authenticate via the /kylin/api/user/authentication endpoint before injecting commands; unauthenticated exploitation is not directly possible.
  • ·Affected versions span Apache Kylin 2.3.0 through 2.6.5 and 3.0.1; detections should be scoped to these versions.

CVSS provenance

nvdv3.18.8HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
nvdv2.09.0CRITICALAV:N/AC:L/Au:S/C:C/I:C/A:C
ghsa8.8HIGH
osv8.8HIGH
vulncheck8.8HIGH
cisa8.8HIGH
CVEs like this are exactly what “Exploited This Week” covers.

Every Monday: what got weaponized or added to CISA KEV in the last seven days — each CVE cross-linked to its PoC, Nuclei template, and detection rule. Free, one email a week, unsubscribe in one click.