Alexandr Savca

Security Engineer — Application Security, Penetration Testing & Vulnerability Research

Email · GitHub · LinkedIn · Website
Republic of Moldova

Security engineer and systems programmer with more than twelve years across Linux infrastructure, software security, and network protocols. Professional application-security experience at Salt Edge and independent security research since 2020. Experienced in white- and black-box assessment, source-code review, threat modeling, vulnerability validation, remediation, and security tooling.

Core Expertise

Application security: web and API testing, source-code review, threat modeling, authentication and authorization, vulnerability triage, remediation verification
Security research: vulnerability analysis, proof-of-concept development, reverse engineering, protocol analysis
Systems: Linux, systems programming, debugging, infrastructure, performance analysis
Programming: C, C++, Python, Perl, shell, Tcl/Tk
Network analysis: Wireshark, Zeek, Nmap, HTTP, DNS, VPN, mail protocols, Oracle TNS

Selected Achievements

Disclosed five vulnerabilities: CVE-2020-36420, CVE-2021-38614, CVE-2021-31799, CVE-2021-31810, and CVE-2021-32066
Extended Wireshark’s Oracle TNS dissector with protocol parsing, authentication, session-key, and packet-handling improvements
Contributed support for ELAN0618 hardware to the Linux kernel input subsystem
Contributed accepted C and documentation fixes to Perl 5 and am listed in its upstream AUTHORS file
Designed the modular package-management architecture used by the Zeppe-Lin GNU/Linux project

Experience

Independent Security Engineer & Systems Programmer

Jan 2020 – Present

Conduct authorized application assessments and source-code reviews, tracing authentication, authorization, data flow, and trust boundaries
Develop reproducible proof-of-concept exploits and verification tools for confirmed vulnerabilities
Research vulnerabilities in Ruby libraries and network services, resulting in five coordinated CVE disclosures
Build and maintain security tools and automation, including pdf2hashcat and Pixload
Design and maintain Zeppe-Lin’s Linux and package-management architecture, with explicit execution, state, recovery, and authority boundaries
Contribute fixes to security tools and Linux-based systems and maintain operational documentation

Information Security Engineer — Salt Edge

Jan 2018 – Nov 2019

Performed white- and black-box application security testing, manual source-code review, and threat modeling
Designed and operated the company’s bug bounty program, triaged external reports, and coordinated remediation
Translated security findings into remediation requirements and verified implemented fixes
Reviewed proposed designs and helped engineering teams apply secure design principles across projects

System Programmer (Freelance)

Sep 2016 – Feb 2017

Reverse engineered network protocols and documented observed behavior
Developed Zeek (Bro) IDS plugins for protocol visibility and detection
Analyzed Oracle TNS traffic and contributed dissector improvements upstream

System Administrator (Freelance)

2012 – 2017

Administered Linux infrastructure across DNS, VPN, web, database, and mail services
Tuned kernel and system performance and investigated network and service failures
Developed operational automation in C, shell, Perl, and Tcl/Tk

Selected Research & Writing

The Fieldbook (2026)

Author of The Fieldbook, a technical book presenting a practical method for analyzing authority boundaries, contracts, invariants, semantic drift, system failure, intervention, and verification in long-lived infrastructure.

sighook.im