Red Hat has released a security advisory and updated packages to address the Squid Web Proxy Cache string.cci remote denial of service vulnerability.
Squid Web Proxy Cache versions prior to 3.1.8 contain a vulnerability that could allow an authenticated, remote attacker to cause a denial of service (DoS) condition on the targeted system.
The vulnerability is due to a memory corruption error in the affected software while handling HTTP requests. An authenticated, remote attacker could exploit the vulnerability by sending crafted requests to the affected system. Processing these requests could cause a pointer dereference error, corrupting memory. The memory corruption could cause an unexpected termination of the application, denying service to legitimate users.
Squid has confirmed the vulnerability and released updated software.
Squid Web Proxy Cache versions prior to 3.1.8 are vulnerable.
To exploit the vulnerability, an attacker needs to be authenticated to the system, which somewhat reduces the likelihood of an attack.
Reports suggest that binaries built with --disable-http-violations are not vulnerable. Squid versions where the squid.conf file is configured with the ignore_expect_100 on directive are vulnerable. Additional Squid development versions prior to 22.214.171.124 are also vulnerable.
A successful exploit could lead to a DoS condition in the context of the affected service only. Restarting the service will resume normal operation of the vulnerable software.
The vulnerability could be triggered accidentally by client browser applications that reference Squid. The vendor has confirmed that applications that may trigger accidental exploits exist publicly.
Squid has released a security advisory at the following link: SQUID-2010:3
Red Hat has released a security advisory at the following link: RHSA-2011:0545
An authenticated, remote attacker could exploit this vulnerability to cause a DoS condition, causing the application to terminate unexpectedly and deny access to legitimate users.
The vulnerability is in the strcmp() function in the string.cci source file of the affected software due to a memory error while handling HTTP requests. An authenticated, remote attacker could exploit the vulnerability by transmitting crafted HTTP requests to the affected software. This could trigger a NULL pointer dereference error, causing the affected service to crash and resulting in a DoS condition.
Administrators are advised to apply the appropriate updates.
Administrators are advised to allow only trusted users to have network access.
Administrators are advised to implement an intrusion prevention system (IPS) or intrusion detection system (IDS) to help detect and prevent attacks that attempt to exploit this vulnerability.
Administrators are advised to configure the Squid instance with --disable-http-violations.
Administrators are advised to monitor affected systems.
Squid has released updated software at the following link: 3.1.8
Version 1, September 27, 2010, 8:25 AM: Squid Web Proxy Cache contains a vulnerability that could allow an authenticated, remote attacker to cause a denial of service condition on the targeted system. Updates are available.
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