Vulnerabilities > CVE-2011-4357 - USE of Externally-Controlled Format String vulnerability in Brandon Long Clearsilver
Attack vector
NETWORK Attack complexity
LOW Privileges required
NONE Confidentiality impact
PARTIAL Integrity impact
PARTIAL Availability impact
PARTIAL Summary
Format string vulnerability in the p_cgi_error function in python/neo_cgi.c in the Python CGI Kit (neo_cgi) module for Clearsilver 0.10.5 and earlier allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via format string specifiers that are not properly handled when creating CGI error messages using the cgi_error API function.
Vulnerable Configurations
Common Weakness Enumeration (CWE)
Common Attack Pattern Enumeration and Classification (CAPEC)
- Format String Injection An attacker includes formatting characters in a string input field on the target application. Most applications assume that users will provide static text and may respond unpredictably to the presence of formatting character. For example, in certain functions of the C programming languages such as printf, the formatting character %s will print the contents of a memory location expecting this location to identify a string and the formatting character %n prints the number of DWORD written in the memory. An attacker can use this to read or write to memory locations or files, or simply to manipulate the value of the resulting text in unexpected ways. Reading or writing memory may result in program crashes and writing memory could result in the execution of arbitrary code if the attacker can write to the program stack.
- String Format Overflow in syslog() This attack targets the format string vulnerabilities in the syslog() function. An attacker would typically inject malicious input in the format string parameter of the syslog function. This is a common problem, and many public vulnerabilities and associated exploits have been posted.
Nessus
NASL family Fedora Local Security Checks NASL id FEDORA_2011-17040.NASL description This update fixes : - Bug #757543 - clearsilver (neo_cgi): Format string flaw by processing CGI error messages in Python module [fedora-all] Note that Tenable Network Security has extracted the preceding description block directly from the Fedora security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues. last seen 2020-06-01 modified 2020-06-02 plugin id 57383 published 2011-12-23 reporter This script is Copyright (C) 2011-2019 Tenable Network Security, Inc. source https://www.tenable.com/plugins/nessus/57383 title Fedora 15 : clearsilver-0.10.5-15.fc15 (2011-17040) NASL family Fedora Local Security Checks NASL id FEDORA_2011-17042.NASL description This update fixes : - Bug #757543 - clearsilver (neo_cgi): Format string flaw by processing CGI error messages in Python module [fedora-all] Note that Tenable Network Security has extracted the preceding description block directly from the Fedora security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues. last seen 2020-06-01 modified 2020-06-02 plugin id 57384 published 2011-12-23 reporter This script is Copyright (C) 2011-2019 Tenable Network Security, Inc. source https://www.tenable.com/plugins/nessus/57384 title Fedora 16 : clearsilver-0.10.5-15.fc16 (2011-17042) NASL family Debian Local Security Checks NASL id DEBIAN_DSA-2355.NASL description Leo Iannacone and Colin Watson discovered a format string vulnerability in the Python bindings for the Clearsilver HTML template system, which may lead to denial of service or the execution of arbitrary code. last seen 2020-03-17 modified 2011-12-02 plugin id 56986 published 2011-12-02 reporter This script is Copyright (C) 2011-2020 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/56986 title Debian DSA-2355-1 : clearsilver - format string vulnerability
References
- http://code.google.com/p/clearsilver/source/detail?r=919
- http://osvdb.org/77419
- http://secunia.com/advisories/47016
- http://tech.groups.yahoo.com/group/ClearSilver/message/1422
- http://www.debian.org/security/2011/dsa-2355
- http://www.openwall.com/lists/oss-security/2011/11/27/1
- https://exchange.xforce.ibmcloud.com/vulnerabilities/71599