SB2021022802 - Multiple vulnerabilities in Privoxy

Description

This security bulletin contains information about 5 secuirty vulnerabilities.

1) Reachable Assertion (CVE-ID: CVE-2021-20272)

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

The vulnerability exists due to a reachable assertion within the ssplit() function when processing CGI requests. A remote attacker can send a specially crafted CGI request, trigger an assertion failure and crash the service.

2) Input validation error (CVE-ID: CVE-2021-20273)

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

The vulnerability exists due to insufficient validation of user-supplied input within the cgi_send_banner() function. A remote attacker can pass specially crafted CGI request with an invalid image type and perform a denial of service (DoS) attack.

3) NULL pointer dereference (CVE-ID: CVE-2021-20274)

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

The vulnerability exists due to a NULL pointer dereference error within the socks5_connect() function, when sending empty credentials. A remote attacker can perform a denial of service (DoS) attack.

4) Out-of-bounds read (CVE-ID: CVE-2021-20275)

The vulnerability allows a remote attacker to gain access to potentially sensitive information.

The vulnerability exists due to a boundary condition within the chunked_body_is_complete() function. A remote attacker can send specially crafted data to the application, trigger an out-of-bounds read error and read contents of memory on the system.

5) Out-of-bounds read (CVE-ID: CVE-2021-20276)

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

The vulnerability exists due to a boundary condition when processing patterns passed to pcre_compile() function. A remote attacker can pass specially crafted data to the application, trigger out-of-bounds read error and perform a denial of service (DoS) attack.

Remediation

Install update from vendor's website.

References

• https://lists.privoxy.org/pipermail/privoxy-announce/2021-February/000007.html
• http://seclists.org/oss-sec/2021/q1/197