CVE-2021-20212

A flaw was found in Privoxy in versions before 3.0.29. Memory leak if multiple filters are executed and the last one is skipped due to a pcre error leading to a system crash.

Weakness

The product does not sufficiently track and release allocated memory after it has been used, making the memory unavailable for reallocation and reuse.

Affected Software

Potential Mitigations

• Choose a language or tool that provides automatic memory management, or makes manual memory management less error-prone.
• For example, glibc in Linux provides protection against free of invalid pointers.
• When using Xcode to target OS X or iOS, enable automatic reference counting (ARC) [REF-391].
• To help correctly and consistently manage memory when programming in C++, consider using a smart pointer class such as std::auto_ptr (defined by ISO/IEC ISO/IEC 14882:2003), std::shared_ptr and std::unique_ptr (specified by an upcoming revision of the C++ standard, informally referred to as C++ 1x), or equivalent solutions such as Boost.

References

• https://bugzilla.redhat.com/show_bug.cgi?id=1928736
• https://security.gentoo.org/glsa/202107-16
• https://www.privoxy.org/3.0.29/user-manual/whatsnew.html
• https://bugzilla.redhat.com/show_bug.cgi?id=1928736
• https://security.gentoo.org/glsa/202107-16
• https://www.privoxy.org/3.0.29/user-manual/whatsnew.html