The aclMatchExternal function in Squid before 2.6.STABLE7 allows remote attackers to cause a denial of service (crash) by causing an external_acl queue overload, which triggers an infinite loop.

- This update fixes a remotely exploitable     denial-of-service bug in squid, that can be triggered by     using special ftp:// URLs. (CVE-2007-0247)

  - The packages are not vulnerable to a bug in external     ACLs. (CVE-2007-0248)

David Duncan Ross Palmer and Henrik Nordstrom discovered that squid incorrectly handled special characters in FTP URLs. Remote users with access to squid could crash the server leading to a denial of service.
(CVE-2007-0247)

Erick Dantas Rotole and Henrik Nordstrom discovered that squid could end up in an endless loop when exhausted of available external ACL helpers. Remote users with access to squid could cause CPU starvation, possibly leading to a denial of service. This does not affect a default Ubuntu installation, since external ACL helpers must be configured and used. (CVE-2007-0248).

Note that Tenable Network Security has extracted the preceding description block directly from the Ubuntu security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

This update fixes a remotely exploitable denial-of-service bug in squid, that can be triggered by using special ftp:// URLs.
(CVE-2007-0247) Additionally the 10.2 package needed a fix for another DoS bug (CVE-2007-0248) and for max_user_ip handling in ntlm_auth.

Two vulnerabilities have been reported in Squid, which can be exploited by malicious people to cause a denial of service.

A vulnerability in squid was discovered that could be remotely exploited by using a special ftp:// URL (CVE-2007-0247).

Another Denial of Service vulnerability was discovered in squid 2.6 that allows remote attackers to crash the server by causing an external_acl_queue overload (CVE-2007-0248).

Additionally, a bug in squid 2.6 for max_user_ip handling in ntlm_auth has been corrected.

The updated packages have been patched to correct this problem.

The remote host is affected by the vulnerability described in GLSA-200701-22 (Squid: Multiple Denial of Service vulnerabilities)

    Squid fails to correctly handle ftp:// URI's. There is also an error in     the external_acl queue which can cause an infinite looping condition.
  Impact :

    An attacker could attempt to retrieve a specially crafted URI via a     Squid server causing the service to crash. If an attacker could     generate a sufficiently high load on the Squid services, they could     cause a Denial of Service by forcing Squid into an infinite loop.
  Workaround :

    There is no known workaround at this time.

The remote Squid caching proxy, according to its version number, is vulnerable to multiple attack vectors. At the least, attackers would be able to crash the service.

ID	Name	Product	Family	Severity
41115	SuSE9 Security Update : squid (YOU Patch Number 11402)	Nessus	SuSE Local Security Checks	medium
28003	Ubuntu 6.06 LTS / 6.10 : squid vulnerabilities (USN-414-1)	Nessus	Ubuntu Local Security Checks	medium
27452	openSUSE 10 Security Update : squid (squid-2504)	Nessus	SuSE Local Security Checks	medium
24870	Squid < 2.6.STABLE7 Multiple Remote DoS	Nessus	Firewalls	medium
24640	Mandrake Linux Security Advisory : squid (MDKSA-2007:026)	Nessus	Mandriva Local Security Checks	medium
24258	GLSA-200701-22 : Squid: Multiple Denial of Service vulnerabilities	Nessus	Gentoo Local Security Checks	medium
3887	Squid < 2.6.STABLE7 Multiple Vulnerabilities	Nessus Network Monitor	Web Servers	medium

Detections

Analytics

CVE-2007-0248

high

Tenable Plugins

medium

medium

medium

medium

medium

medium

medium