F5 Big IP opens up vulnerability during configuration
.png)
F5 Networks’ popular load balancing software BIG-IP harbours a vulnerability that could let malicious code seep in using just an online form.
"Load balancing is an important web management process that keeps many internet services ticking," said F-Secure, which spotted the vulnerability. "Without it, banks, governments, and other organisations providing online services to large numbers of people would struggle to keep their websites running."
Senior security consultant Christoffer Jerkeby discovered the vulnerability during a routine assessment. More than 300,000 organisations including state bodies and large banks use BIG-IP, broadening the scope of potential damages.
"Further research found that, following a successful exploit, an adversary could turn the compromised device back against the organisation or even individuals using the affected services," it added.
F-Secure said it is yet to receive reports of misuse of this vulnerability.
"F5 is a popular technology and we found over 300,000 (potentially vulnerable) devices on-line. Google and services like Shodan can be used to search for these also. The F5 website also contains information on their clients and sectors," Dave Hartley, technical director at F-Secure, told SC Media UK.
He refrained from revealing the names of the vulnerable F5 clients, saying: "These companies may be at risk of compromise."
Curiously, BIG-IP itself is immune to the vulnerability. It creeps up only when an organisation mis-configures BIG-IP’s iRules, the procedures written in tool command language (Tcl) to direct incoming web traffic toward the correct web server.
"These iRules are created using the tool command language (Tcl). Certain coding practices that may seem perfectly functional and practical to an organisation can allow an attacker to inject arbitrary Tcl commands, which could be executed in the security context of the target Tcl script," the report said.
In some implementations of BIG-IP, injecting a malicious code can be as easy as filling an online form, F-Secure revealed.
The threat posed is way bigger than a simple data breach, Hartley told SC Media UK. "An attacker can leverage the issue to achieve much more than a data breach alone. If the prerequisites are met, it could result in an adversary taking full control of the F5."
However, the scope and depth of the attack will vary, depending on the objective of the attacker and the scale of operations of the target organisation, he said.
"The F5 is often used for perimeter security and traffic management and there have been issues identified in similar technologies in the past that have had a severe impact for some -- firewalls, anti-virus, e-mail sandbox technologies etc.," he explained.
Addressing the issue, F5 released a public advisory.
"This is not a vulnerability in Tcl, or F5 products, but rather an issue relating to coding practices used when writing Tcl code. As with most programming or scripting languages, it is possible to write code in a way that may create vulnerabilities. This is not something F5 can prevent the user from doing, as the issue does not lend itself to neither deterministic nor heuristic detection that covers all possible cases," it said.
"The Tcl documentation previously cited provides more comprehensive recommendations. However, the simple answer is that expressions in Tcl should always be braced," it added.
source scmagazineuk
Industry: Cyber Security

Latest Jobs
-
- Account Manager - IT Services
- Germany
- €90000 plus OTE and Car
-
Are you a deal closer with a hunter mindset? Do you know how to uncover business pain points, and turn them into long-term digital transformation partnerships? Our Client are growing their sales force across Germany and looking for an ambitious, straight-talking Account Manager to take the lead on new client acquisition. You’ll focus on mid-sized to large enterprises across Germany helping to shape their digital future with tailored IT solutions in Workplace, Cloud, and Security. • Drive Growth: Own the full sales cycle for new business across your region. • Solution Sell: Build bespoke offers in Security, Digital Workplace and Cloud solutions • Build Relationships: Establish a solid pipeline through smart prospecting, marketing-driven leads, and your own network. • Represent a brand known for trust, delivery, and tech excellence—with 4,000 employees globally and a growing team within Germany. What You Bring • Proven new logo sales experience in the IT services space (not hardware!) • Deep knowledge in one or more of: Cybersecurity, Digital Workplace, or Cloud • Confidence to lead enterprise deals and pitch directly to senior stakeholders • Fluent German and good English skills Sind Sie ein Abschlussprofi mit Hunter-Mentalität? Wissen Sie, wie man geschäftliche Pain Points identifiziert und in langfristige Partnerschaften zur digitalen Transformation verwandelt? Unser Kunde baut derzeit sein Vertriebsteam in ganz Deutschland aus und sucht eine ambitionierte, ehrliche Persönlichkeit als Account Manager, die den Lead bei der Neukundengewinnung übernimmt. Ihr Fokus liegt auf mittelständischen bis großen Unternehmen in Deutschland, denen Sie mit maßgeschneiderten IT-Lösungen in den Bereichen Workplace, Cloud und Security den Weg in die digitale Zukunft ebnen. Ihre Aufgaben • Wachstum vorantreiben: Verantwortung für den gesamten Vertriebszyklus im Neugeschäft Ihrer Region. • Lösungsorientierter Vertrieb: Entwicklung individueller Angebote in den Bereichen Security, Digital Workplace und Cloud-Lösungen. • Beziehungen aufbauen: Aufbau einer stabilen Pipeline durch gezielte Ansprache, marketinggenerierte Leads und Ihr eigenes Netzwerk. • Marke repräsentieren: Werden Sie Teil eines Unternehmens mit 4.000 Mitarbeitenden weltweit und einem stark wachsenden Team in Deutschland – bekannt für Vertrauen, Verlässlichkeit und technologische Exzellenz. Was Sie mitbringen • Nachgewiesene Erfahrung in der Neukundenakquise im Bereich IT-Services (kein Hardwarevertrieb!) • Fundiertes Wissen in mindestens einem der Bereiche: Cybersecurity, Digital Workplace oder Cloud • Selbstbewusstes Auftreten im Umgang mit Enterprise-Deals und Entscheidungsträgern auf Top-Level • Verhandlungssichere Deutschkenntnisse und gute Englischkenntnisse
-
- Senior SOC Analyst Level 3. Microsoft Security stack | Ability to achieve SC Clearance
- London
- To attract the right person
-
Job Title: Senior SOC Analyst Level 3. Microsoft Security stack | Ability to achieve SC Clearance Location: Hybrid remote | London / Berkshire Overview: Senior SOC Analyst Level 3 to join a specialist Managed Security Services business. You will be responsible for advanced threat hunting / triage, incident response etc with a strong focus on the Microsoft Security Stack. Key Responsibilities: Lead and resolve complex security incidents / escalations Conduct advanced threat hunting using the Microsoft Security Stack. Build, optimise and maintain workbooks, rules, analytics etc. Correlate data across Microsoft 365 Defender, Azure Defender and Sentinel. Perform root cause analysis and post-incident reporting. Aid in mentoring and upskilling Level 1 and 2 SOC analysts. Required Skills & Experience: The ability to achieve UK Security Clearance (SC) – existing clearance ideal. (Sorry no visa applications) Current experience working with a SOC environment Microsoft Sentinel: Development and tuning of custom analytic rules. Workbook creation and dashboarding. Automation using Playbooks and SOAR integration. Kusto Query Language (KQL): Writing complex, efficient queries for advanced threat hunting and detection. Correlating data across key tables (e.g., SignInLogs, SecurityEvent, OfficeActivity, DeviceEvents). Developing custom detection rules, optimising performance, and reducing false positives. Supporting Sentinel Workbooks, Alerts, and Playbooks through advanced KQL use. Deep understanding of incident response, threat intelligence and adversary techniques (MITRE ATT&CK framework). Strong knowledge of cloud and hybrid security, particularly within Azure. Additional Requirements: Must hold or be eligible to achieve a minimum of Security Clearance (SC) level. Nice to have certifications (e.g., SC-200, AZ-500, GIAC) are desirable. Strong problem-solving and analytical skills. Excellent communication for clear documentation and team collaboration. Please follow Wheaton’s Law.
-
- New Business Sales Hunter | Cyber Security (UK Based)
- London
- To attract the right person
-
New Business Sales Hunter needed | Cybersecurity (UK Based) Are you looking for uncapped commission, a fun and sociable team that drives success with no politics? If so...You must Be UK based - and able to achieve UK SC clearance. (sorry no visas) Have a demonstrable history of sales success in Cyber Security Follow Weatons law. The role: Seeking a proven New Business Sales Hunter to join an established, successful and expanding cyber security firm. New business focused - £1m GP year one target (ramped). Sell a blend of security services & professional services. Ideal experience selling some or all of the following Cyber strategy & risk management Managed detection & response (MDR) Penetration testing Compliance & audit support You: Strong cybersecurity/IT services sales track record. Confident selling into mid-market & enterprise. UK based - London commutable 1x per week. Hunter mindset, full sales cycle ownership. Don't just send an email to apply give me a call on 07884666351
-
- CyberArk Architect
- London
- Upto £110,000 plus bonus and benefits
-
Are you ready to lead from the front and drive innovation in the Identity & Access Management (IAM) space? We’re looking for a seasoned CyberArk Architect who has CDE-CPC ideally or experience with privilege Cloud, someone who can lead with vision, execute with precision, and inspire teams to deliver excellence. As a key leader in our organisation, you’ll bring your strong business acumen and a technology-focused, innovative mindset to the table. You’ll be driving strategic initiatives, shaping transformation programs, and empowering teams to think big and deliver even bigger. Acting as a subject matter expert in CyberArk Leading strategic transformations in: Identity Governance Privileged Access Management (PAM) Access Management Customer Identity and Access Management (CIAM) Building and maintaining strong, collaborative relationships within the team Communicating clearly and confidently — both written and verbal — to deliver updates, raise potential issues, and share insights If you are interested in the above position we are looking for people with: deep expertise and a successful track record in IAM strategy, delivery, or assurance with CyberArk Hold relevant certifications such as CDE in Privileged Cloud or Guardian Have experience in a client-facing role (preferred, but not essential) Thrive in a hybrid working environment and are available to work from our or client London office three days a week Lead with clarity, communicate with impact, and adapt quickly to changing priorities