In software development, investigating the accessibility of dependency vulnerabilities is of great importance, as third-party libraries often contain known vulnerabilities that could be exploited in the application's business logic. The existing accessibility analysis methods encounter challenges such as undecidability, abstraction loss, and path explosion in large-scale programs, resulting in an inaccurate distinction between accessibility vulnerabilities and non-accessibility vulnerabilities. This paper introduces an approach called ConVReach for analyzing the reachability of vulnerabilities in dependencies in C/C++ programs. ConVReach overcomes the problems of high abstraction loss and potential path explosion in the current methods by combining static and dynamic approaches, particularly a constraint-guided analysis method. This approach extracts and decomposes the path constraints that trigger vulnerabilities, independently verifies the satisfiability of each constraint, and then aggregates the feasible paths. This effectively reduces unnecessary path exploration and avoids the common path explosion issues in traditional methods. Experimental results show that ConVReach outperforms existing tools in both accuracy and efficiency, effectively distinguishing between reachable and unreachable vulnerabilities, and significantly reducing false positives and false negatives. We constructed a benchmark dataset to evaluate ConVReach , which includes 53 CVEs and 347 flags artificially inserted into various open-source projects. This dataset was designed to simulate both real-world vulnerabilities and complex scenarios. Through testing on this dataset, ConVReach demonstrated exceptional performance. It successfully identified 59 out of 61 reachable vulnerabilities and all 23 unreachable ones in the CVE dataset. Within a 24-hour time budget, ConVReach detected above 50% more reachable vulnerabilities than the baseline tools in the first 6 hours and nearly completed the detection of reachable vulnerabilities by the 12-hour mark. These results highlight ConVReach 's superior ability to handle both real-world vulnerabilities and challenging cases.

With the escalating threat of software vulnerabilities to the security of modern software systems, an increasing number of deep learning (DL) model-based vulnerability detectors have been developed for vulnerability detection. However, their practical reliability, consistency in usage, and adaptability across diverse software contexts remain unclear. This uncertainty may lead to unreliable detection results in practical applications, increased false positives and false negatives, and limited adaptability to newly emerged vulnerabilities. Conducting a large-scale and in-depth analysis of DL-based vulnerability detectors can help uncover critical factors influencing detection performance, improve the design and training of these models, and enhance their practical deployment in real-world scenarios. In this paper, we present VulTegra, a novel evaluation framework that, for the first time, conducts a multidimensional assessment comparing scratch-trained models and pre-trained-based models for vulnerability detection, while verifying key factors influencing detection performance. Our framework reveals that state-of-the-art (SOTA) detectors still suffer from low consistency, limited practical detection capabilities, and limited adaptability. Moreover, comparative results indicate that the increasingly favored pre-trained-based models are not universally superior to scratch-trained models; instead, they exhibit distinct strengths and application scenarios. Most importantly, our study highlights the limitations of relying solely on CWE-based classification and reveals a set of critical factors that significantly influence detection performance. Experimental validation shows that these factors have a substantial impact: modifying only any single factor led to recall improvements across all seven evaluated SOTA detectors, with six detectors also achieving higher F1 scores. Our findings provide deep insights into model behavior, highlighting the need to consider both vulnerability types and inherent code features to ensure practical applicability in real-world software environments.