Automatic binary patching for flaws repairing using static rewriting and reverse dataflow analysis

Tese de Mestrado, Segurança Informática, 2022, Universidade de Lisboa, Faculdade de CiênciasThe C programming language is widely used in embedded systems, kernel and hardware programming, making it one of the most commonly used programming languages. However, C lacks of boundary verification of variables, making it one of the most vulnerable languages. Because of this and associated with its high usability, it is also the language with most reported vulnerabilities in the past ten years, being the memory corruption the most common type of vulnerabilities, specifically buffer overflows. These vulnerabilities when exploited can produce critical consequences, being thus extremely important not only to correctly identify these vulnerabilities but also to properly fix them. This work aims to study buffer overflow vulnerabilities in C binary programs by identifying possible malicious inputs that can trigger such vulnerabilities and finding their root cause in order to mitigate the vulnerabilities by rewriting the binary assembly code and thus generating a new binary without the original flaw. The main focus of this thesis is the use of binary patching to automatically fix stack overflow vulnerabilities and validate its effectiveness while ensuring that these do not add new vulnerabilities. Working with the binary code of applications and without accessing their source code is a challenge because any required change to its binary code (i.e, assembly) needs to take into consideration that new instructions must be allocated, and this typically means that existing instructions will need to be moved to create room for new ones and recover the control flow information, otherwise the application would be compromised. The approach we propose to address this problem was successfully implemented in a tool and evaluated with a set of test cases and real applications. The evaluation results showed that the tool was effective in finding vulnerabilities, as well as in patching them

Assessment of calcinosis in Portuguese patients with systemic sclerosis: a multicenter study

© The Author(s), under exclusive licence to International League of Associations for Rheumatology (ILAR) 2023Introduction/objectives: The study aims to define the clinical and subclinical calcinosis prevalence, the sensitivity of radiographed site and clinical method for its diagnosis, and the phenotype of Portuguese systemic sclerosis (SSc) patients with calcinosis. Method: A cross-sectional multicenter study was conducted with SSc patients fulfilling Leroy/Medsger 2001 or ACR/EULAR 2013 classification criteria, registered in the Reuma.pt. Calcinosis was assessed through clinical examination and radiographs of hands, elbows, knees, and feet. Independent parametric or non-parametric tests, multivariate logistic regression, and sensitivity calculation of radiographed site and clinical method for calcinosis detection were performed. Results: We included 226 patients. Clinical calcinosis was described in 63 (28.1%) and radiological calcinosis in 91 (40.3%) patients, of which 37 (40.7%) were subclinical. The most sensitive location to detect calcinosis was the hand (74.7%). Sensitivity of the clinical method was 58.2%. Calcinosis patients were more often female (p = 0.008) and older (p < 0.001) and had more frequently longer disease duration (p < 0.001), limited SSc (p = 0.017), telangiectasia (p = 0.039), digital ulcers (p = 0.001), esophageal (p < 0.001) and intestinal (p = 0.003) involvements, osteoporosis (p = 0.028), and late capillaroscopic pattern (p < 0.001). In multivariate analysis, digital ulcers (OR 2.63, 95% CI 1.02-6.78, p = 0.045) predicted overall calcinosis, esophageal involvement (OR 3.52, 95% CI 1.28-9.67, p = 0.015) and osteoporosis (OR 4.1, 95% CI 1.2-14.2, p = 0.027) predicted hand calcinosis, and late capillaroscopic pattern (OR 7.6, 95% CI 1.7-34.9, p = 0.009) predicted knee calcinosis. Anti-nuclear antibody positivity was associated with less knee calcinosis (OR 0.021, 95% CI 0.001-0477, p = 0.015). Conclusions: Subclinical calcinosis high prevalence suggests that calcinosis is underdiagnosed and radiographic screening might be relevant. Multifactorial pathogenesis may explain calcinosis predictors' variability. Key Points • Prevalence of subclinical calcinosis in SSc patients is substantial. • Hand radiographs are more sensitive to detect calcinosis than other locations or clinical method. • Digital ulcers were associated with overall calcinosis, esophageal involvement and osteoporosis were associated with hand calcinosis, and late sclerodermic pattern in nailfold capillaroscopy was associated with knee calcinosis. • Anti-nuclear antibody positivity may be a protective factor for knee calcinosis.info:eu-repo/semantics/publishedVersio

Protein requirements for growth in male and female Saanen goats

The objective of this study was to determine the protein requirements for the growth of intact male, female, and castrated male Saanen goats weighing 30 to 45 kg of body weight (BW) and to compare estimates of the protein requirements for maintenance (NPm) by the comparative slaughter and nitrogen balance techniques. To determine the maintenance requirements, 55 goats were assigned in a split-plot design using a 3 × 3 factorial arrangement (three sexes and three dry matter intake (DMI) levels). A linear regression of retained N (as measured by the slaughter technique and estimated from the nitrogen balance) on N intake on a daily basis was used to calculate the net protein for maintenance. The net protein requirement for weight gain (NPg) was obtained using 65 goats fed ad libitum in a completely randomized design. The first derivative of the allometric equation of protein content in the empty BW with respect to the empty BW yielded estimates of the NPg. According to the comparative slaughter technique, the estimated NPm was 1.46 g/kg of metabolic weight, which is 50% lower than the estimate from the nitrogen balance technique. When evaluating the variance of the error, the nitrogen balance also showed greater values, indicating less precision compared with that of the comparative slaughter technique. The daily NPg ranged from 155.7±10.9 to 153.4±13.5 g/kg of EBW gain for growing Saanen goats. The protein requirements (NPm and NPg) of intact male, female, and castrated male Saanen goats are similar, from 30 to 45 kg BW, in accordance with current feeding systems. Moreover, the results of the present study indicate that the estimate of NPm using the comparative slaughter technique is more precise and lower than that using the N balance technique

Characterisation of microbial attack on archaeological bone

As part of an EU funded project to investigate the factors influencing bone preservation in the archaeological record, more than 250 bones from 41 archaeological sites in five countries spanning four climatic regions were studied for diagenetic alteration. Sites were selected to cover a range of environmental conditions and archaeological contexts. Microscopic and physical (mercury intrusion porosimetry) analyses of these bones revealed that the majority (68%) had suffered microbial attack. Furthermore, significant differences were found between animal and human bone in both the state of preservation and the type of microbial attack present. These differences in preservation might result from differences in early taphonomy of the bones. © 2003 Elsevier Science Ltd. All rights reserved

70º Aniversario de la declaración universal de derechos humanos. La protección internacional de los Derechos Humanos en cuestión

Segundo volúmen de la Colección Perspectivas Iberoamericanas sobre la justicia. La Declaración Universal de los Derechos Humanos de las Naciones Unidas cumple, el 10 de diciembre de 2018, setenta años. La simbólica fecha obliga a los investigadores en derechos humanos a reflexionar críticamente sobre los avances y límites de un complejo sistema de normas y, sobre todo, de valores culturales sustentados en la matriz liberal occidental. Desde entonces, ha habido indiscutibles avances institucionales y normativos, como la creación del Consejo de Derechos Humanos, varios pactos y declaraciones complementarias, órganos específicos, tribunales internacionales, jurisprudencia, constituciones estatales, una infinidad de instituciones basadas en esta “ética mínima universal” que, contradictoriamente, no logró evitar un conjunto de catástrofes humanitarias y de vulneración de derechos. La primera década del siglo XX trae un reflejo limitante al consenso de la posguerra, pues la agresividad de los Estados hegemónicos, en alianza con intereses privados transnacionales, pone en jaque la capacidad del sistema protector frente a guerras humanitarias e internacionales. tratados económicos de nueva generación aquellos que excluyen por completo a la democracia del proceso de negociación.A Declaração Universal dos Direitos Humanos das Nações Unidas completa, em 10 de diciembre de 2018, setenta años. A data simbólica exige dos pesquisadores em direitos humanos uma reflexão crítica a respeito dos avanços y dos limites de um sistema complexo de normas e, principalmente, de valores culturales apoiados na matriz liberal ocidental. De lá para cá, houve indiscutível avanço institucional e normativo, do qual é exemplo a criação do Conselho de Direitos Humanos, diversos pactos e declarações complementarios, órgão específicos, tribunais internacionais, jurisprudência, constituições dos States, uma infinidade de instituições pautadas nesse “mínimo ético universal” que, contraditoriamente, não conseguiu evitar um conjunto de catástrofes humanitárias e de violação de direitos. A primeira década do século XX traz uma reflexão limite para o consenso do pós-guerra, pois a agressividade dos States hegemônicos, em aliança com interesses private transnacionais, põe em check a capacidade do sistema protectivo diante das guerras humanitárias e dos tratados internacionais econômicos de nueva generación aqueles que excluem completamente a democracia do processo negociador

Mitochondria and Reactive Oxygen Species in Aging and Age-Related Diseases

Aging has been linked to several degenerative processes that, through the accumulation of molecular and cellular damage, can progressively lead to cell dysfunction and organ failure. Human aging is linked with a higher risk for individuals to develop cancer, neurodegenerative, cardiovascular, and metabolic disorders. The understanding of the molecular basis of aging and associated diseases has been one major challenge of scientific research over the last decades. Mitochondria, the center of oxidative metabolism and principal site of reactive oxygen species (ROS) production, are crucial both in health and in pathogenesis of many diseases. Redox signaling is important for the modulation of cell functions and several studies indicate a dual role for ROS in cell physiology. In fact, high concentrations of ROS are pathogenic and can cause severe damage to cell and organelle membranes, DNA, and proteins. On the other hand, moderate amounts of ROS are essential for the maintenance of several biological processes, including gene expression. In this review, we provide an update regarding the key roles of ROS–mitochondria cross talk in different fundamental physiological or pathological situations accompanying aging and highlighting that mitochondrial ROS may be a decisive target in clinical practice

Evaluation of a quality improvement intervention to reduce anastomotic leak following right colectomy (EAGLE): pragmatic, batched stepped-wedge, cluster-randomized trial in 64 countries

Background Anastomotic leak affects 8 per cent of patients after right colectomy with a 10-fold increased risk of postoperative death. The EAGLE study aimed to develop and test whether an international, standardized quality improvement intervention could reduce anastomotic leaks. Methods The internationally intended protocol, iteratively co-developed by a multistage Delphi process, comprised an online educational module introducing risk stratification, an intraoperative checklist, and harmonized surgical techniques. Clusters (hospital teams) were randomized to one of three arms with varied sequences of intervention/data collection by a derived stepped-wedge batch design (at least 18 hospital teams per batch). Patients were blinded to the study allocation. Low- and middle-income country enrolment was encouraged. The primary outcome (assessed by intention to treat) was anastomotic leak rate, and subgroup analyses by module completion (at least 80 per cent of surgeons, high engagement; less than 50 per cent, low engagement) were preplanned. Results A total 355 hospital teams registered, with 332 from 64 countries (39.2 per cent low and middle income) included in the final analysis. The online modules were completed by half of the surgeons (2143 of 4411). The primary analysis included 3039 of the 3268 patients recruited (206 patients had no anastomosis and 23 were lost to follow-up), with anastomotic leaks arising before and after the intervention in 10.1 and 9.6 per cent respectively (adjusted OR 0.87, 95 per cent c.i. 0.59 to 1.30; P = 0.498). The proportion of surgeons completing the educational modules was an influence: the leak rate decreased from 12.2 per cent (61 of 500) before intervention to 5.1 per cent (24 of 473) after intervention in high-engagement centres (adjusted OR 0.36, 0.20 to 0.64; P &lt; 0.001), but this was not observed in low-engagement hospitals (8.3 per cent (59 of 714) and 13.8 per cent (61 of 443) respectively; adjusted OR 2.09, 1.31 to 3.31). Conclusion Completion of globally available digital training by engaged teams can alter anastomotic leak rates. Registration number: NCT04270721 (http://www.clinicaltrials.gov)