Summary
CRLF injection in httplib2
Workarounds
Create URI with urllib.parse family functions: urlencode, urlunsplit.
user_input = " HTTP/1.1\r\ninjected: attack\r\nignore-http:"
-uri = "https://api.server/?q={}".format(user_input)
+uri = urllib.parse.urlunsplit(("https", "api.server", "/v1", urllib.parse.urlencode({"q": user_input}), ""))
http.request(uri)
References
https://cwe.mitre.org/data/definitions/93.html
https://docs.python.org/3/library/urllib.parse.html
Thanks to Recar https://github.com/Ciyfly for finding vulnerability and discrete notification.
For more information
If you have any questions or comments about this advisory:
- Open an issue in httplib2
- Email current maintainer at 2020-05
Impact
Attacker controlling unescaped part of uri for httplib2.Http.request() could change request headers and body, send additional hidden requests to same server.
Impacts software that uses httplib2 with uri constructed by string concatenation, as opposed to proper urllib building with escaping.
CVE-2020-11078 has a CVSS score of 6.8 (Medium). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (0.18.0); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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See it in your environmentNew to Kodem? Get a demo →Remediation advice
Problem has been fixed in 0.18.0
Space, CR, LF characters are now quoted before any use.
This solution should not impact any valid usage of httplib2 library, that is uri constructed by urllib.
Frequently Asked Questions
- What is CVE-2020-11078? CVE-2020-11078 is a medium-severity security vulnerability in httplib2 (pip), affecting versions < 0.18.0. It is fixed in 0.18.0.
- How severe is CVE-2020-11078? CVE-2020-11078 has a CVSS score of 6.8 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of httplib2 are affected by CVE-2020-11078? httplib2 (pip) versions < 0.18.0 is affected.
- Is there a fix for CVE-2020-11078? Yes. CVE-2020-11078 is fixed in 0.18.0. Upgrade to this version or later.
- Is CVE-2020-11078 exploitable, and should I be worried? Whether CVE-2020-11078 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2020-11078 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2020-11078? Upgrade
httplib2to 0.18.0 or later.