security Online Quiz - 11

All options are valid measures to prevent Database Access Control attacks. Access control must be enforced at both application and database layers (defense-in-depth). Including the authenticated username in queries ties operations to specific users. Never trusting presentation layer validation prevents bypass attacks. Option D correctly captures that all these practices are necessary.

SQL injection occurs when user-supplied data is used to dynamically construct SQL queries without proper validation or parameterization, allowing attackers to manipulate query structure. Option A describes the flow but not the vulnerability mechanism. Option C describes a different scenario. SQL injection is specifically about the DYNAMIC construction of queries from untrusted input.

CSRF vulnerabilities arise when applications rely on automatically transmitted session cookies, execute requests without explicit user consent checks, and fail to use unpredictable, transaction-specific nonces. Since all these conditions facilitate Cross-Site Request Forgery, all options are correct.

The readLine() method in Java reads input until a line delimiter is found. If an attacker sends a continuous stream of data without newlines, it can exhaust heap space and trigger an OutOfMemoryError, causing a denial of service.

Session hijacking specifically means taking over an existing TCP session between a client and server. The attacker steals or intercepts session tokens (like session IDs or cookies) to impersonate the victim. Monitoring (A, B) is passive observation, not takeover. UDP (C) is connectionless and doesn't maintain sessions in the same way TCP does. Session hijacking targets the stateful nature of TCP connections.

In network-level TCP session hijacking, predicting or intercepting the TCP sequence number is critical for injecting unauthorized data packets into the active stream. Application-level hijacking relies on session IDs, while source IP addresses alone do not enable packet injection.

Input field length validation directly checks that incoming data does not exceed buffer capacities, preventing buffer overflow vulnerabilities. Encryption protects confidentiality, firewalls control network access, and web forms are interface components; none of these address memory bounds directly.

Encryption (such as SSL/TLS or HTTPS) encrypts session communication, preventing attackers from sniffing or intercepting session tokens over the network. Firewalls, strong passwords, and session monitoring are insufficient because they cannot prevent passive sniffing of unencrypted IDs in transit.

MD5 is a hashing algorithm designed to produce a fixed 128-bit digest from inputs of any length. SHA variants produce digests of 160 bits or larger, while RC4 and RC6 are symmetric stream and block ciphers rather than hashing functions.

Substitution is a classical cipher process where plaintext characters are replaced with other characters to obscure content. Transposition reorganizes characters without modifying their identities. Subtraction and transrelation are not standard cryptographic concepts used for mapping characters.

The jill.c (or JilWIN_32) exploit targets a buffer overflow vulnerability (MS01-023) in Microsoft IIS 5.0's Internet Printing Protocol (IPP) ISAPI extension. It allows remote attackers to execute arbitrary system code, whereas blank passwords and SQL injection are unrelated.

Cross-Site Scripting (XSS) occurs when vulnerable code executes malicious scripts in a victim's browser, enabling attackers to hijack sessions, deface sites, or distribute malware. SQL Injection targets databases, while CSRF triggers unauthorized actions, and broken session management exposes user tokens.

Application security alone is NOT sufficient for database security. Databases require additional hardening measures like encryption at rest, access controls, auditing, parameterized queries, and least-privilege configurations. Option C correctly identifies that database-specific hardening is still necessary. Options B and D are partially correct but C is the most precise answer.

Subject.doAs() executes a specified action as a particular JAAS Subject, associating it with the current thread of execution. Other methods like checkPermission() and checkAccess() only verify authorization policies and do not bind or manage user identities on threads.

Double free is a memory corruption vulnerability where free() is called twice on the same pointer. This can corrupt heap metadata, leading to crashes or arbitrary code execution. It is absolutely a security issue (D is wrong). The second free() does NOT necessarily return an error (B is wrong). The program will NOT run fine (C is wrong). Double free must be prevented by setting pointers to NULL after freeing or using memory-safe practices.

In line 1, the loop condition is i <= 3. Since chararray is of size 3 and intarray is of size 3, writing to index 3 (when i == 3) results in an out-of-bounds write (buffer overflow) for both arrays. Hence, line 1 is the source of the loop boundary vulnerability.

Using strncpy(dst, src, sizeof(dst) - 1) ensures that we do not overflow the destination buffer and reserves space to manually append a null terminator \0 at dst[sizeof(dst)-1], making it the most secure of the options.

Using scanf("%8s", name) restricts the input to a maximum of 8 characters (plus a null terminator), preventing buffer overflow if name is sufficiently sized. %s is unbounded, while %.8s is invalid for scanf input.

To limit the input length in C++ std::cin stream extractions, the manipulator setw or cin.width(n) is used. The syntax cin.width[20] contains a typo (should be parenthesis cin.width(20)), but it refers to using the width member function to prevent buffer overflow.