rbpdf-font

Problem

Software license is a legal instrument that governs the use and distribution of software source code and its binary representation. Software publishers have the freedom to choose any commonly used or purposefully written license to publish their work under. While some licenses are liberal and allow almost any kind of distribution, with or without code modification, other licenses are more restrictive and impose rules for their inclusion in other software projects. Copyleft licenses in particular impose substantial restrictions on the licensee. They typically require that any derived works, and even software code that merely interacts with copyleft code, be licensed under the same license. Since copyleft licenses are commonly applied to open source code, their inclusion requires that the entire software package becomes open sourced. For commercial applications, this is typically undesirable. Therefore, the inclusion of copyleft code is commonly avoided or even prohibited by the organization policy.

Problem

Software license is a legal instrument that governs the use and distribution of software source code and its binary representation. Software publishers have the freedom to choose any commonly used or purposefully written license to publish their work under. While some licenses are liberal and allow almost any kind of distribution, with or without code modification, other licenses are more restrictive and impose rules for their inclusion in other software projects. Some software licenses place restrictions on software distribution of the code they apply to. These restrictions may extend to the services built upon the code licensed under such restrictive licenses. Some restrictive licenses explicitly state that the licensee may not provide the software to third parties as a hosted or managed service, where the service provides users with access to any substantial set of the features or functionality of the licensed software. When building commercial applications, this is typically undesirable. Therefore, the inclusion of any code that may impose limits on software distribution is commonly avoided or even prohibited by the organization policy.

Problem

ASLR (address-space layout randomization) is a mitigation technique that increases the difficulty of performing buffer-overflow attacks that require the attacker to know the address of the program in memory. This is done by loading the program at a randomly selected address in the process' address space. ASLR-enabled kernels can choose a random load address only for position-independent executables and code.

Problem

On Linux, external symbols are resolved via the procedure linkage table (PLT) and the global offset table (GOT). Without any protection, both are writable at runtime and thus leave the executable vulnerable to pointer hijacking - an attack where the function address is overwritten with an address of a malicious function. Pointer hijacking can be mitigated by using full read-only relocations, which instruct the compiler to unify global offset tables into a single read-only table. This requires that all external function symbols are resolved at load-time instead of during execution, and may increase loading time for large programs.

Problem

Debug databases are typically only used during software development. On Windows, they are usually files embedded into the executable (PDB), while on Linux, they're contained inside special executable sections. The databases contain private debug symbols that make it significantly easier to reverse-engineer a closed-source application. In some cases, having a debug database is equivalent to having access to the source code. Presence of debug databases could indicate that one or more software components have been built using a debug profile, instead of the release. Private debug databases can be embedded into software components by programming language tools.