Denial of service in httplib2

Published: 2021-02-28
Risk Medium
Patch available YES
Number of vulnerabilities 1
CVE-ID CVE-2021-21240
Exploitation vector Network
Public exploit N/A
Vulnerable software
Other software / Other software solutions

Vendor httplib2

Security Bulletin

This security bulletin contains one medium risk vulnerability.

1) Resource exhaustion

EUVDB-ID: #VU50989

Risk: Medium


CVE-ID: CVE-2021-21240

CWE-ID: CWE-400 - Resource exhaustion

Exploit availability: No


The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to application does not properly control consumption of internal resources. A remote attacker can trigger resource exhaustion by tricking the application to connect to a malicious server that responds with long series of "xa0" characters in the "www-authenticate" header.


Install updates from vendor's website.

Vulnerable software versions

httplib2: 0.9 - 0.18.1

CPE2.3 External links

Q & A

Can this vulnerability be exploited remotely?

Is there known malware, which exploits this vulnerability?