urllib3 handles redirects and retries using the same mechanism, which is controlled by the Retry object. The most common way to disable redirects is at the request level, as follows:
resp = urllib3.request("GET", "https://httpbin.org/redirect/1", redirect=False)
print(resp.status)
# 302However, it is also possible to disable redirects, for all requests, by instantiating a PoolManager and specifying retries in a way that disable redirects:
import urllib3
http = urllib3.PoolManager(retries=0) # should raise MaxRetryError on redirect
http = urllib3.PoolManager(retries=urllib3.Retry(redirect=0)) # equivalent to the above
http = urllib3.PoolManager(retries=False) # should return the first response
resp = http.request("GET", "https://httpbin.org/redirect/1")However, the retries parameter is currently ignored, which means all the above examples don't disable redirects.
Affected usages
Passing retries on PoolManager instantiation to disable redirects or restrict their number.
By default, requests and botocore users are not affected.
Impact
Redirects are often used to exploit SSRF vulnerabilities. An application attempting to mitigate SSRF or open redirect vulnerabilities by disabling redirects at the PoolManager level will remain vulnerable.
Remediation
You can remediate this vulnerability with the following steps:
- Upgrade to a patched version of urllib3. If your organization would benefit from the continued support of urllib3 1.x, please contact [email protected] to discuss sponsorship or contribution opportunities.
- Disable redirects at the
request() level instead of the PoolManager() level.
References
sandumjacob Reporter
illia-v Remediation developer
pquentin Remediation reviewer
sethmlarson Remediation reviewer
urllib3 handles redirects and retries using the same mechanism, which is controlled by the
Retryobject. The most common way to disable redirects is at the request level, as follows:However, it is also possible to disable redirects, for all requests, by instantiating a
PoolManagerand specifyingretriesin a way that disable redirects:However, the
retriesparameter is currently ignored, which means all the above examples don't disable redirects.Affected usages
Passing
retriesonPoolManagerinstantiation to disable redirects or restrict their number.By default, requests and botocore users are not affected.
Impact
Redirects are often used to exploit SSRF vulnerabilities. An application attempting to mitigate SSRF or open redirect vulnerabilities by disabling redirects at the PoolManager level will remain vulnerable.
Remediation
You can remediate this vulnerability with the following steps:
request()level instead of thePoolManager()level.References