Loading vulnerability…
CVE-2021-31886 is a pre-authentication stack-based buffer overflow in the Nucleus FTP server used by Siemens APOGEE, Desigo, Nucleus, and TALON products, and incorporated into affected embedded devices including certain WAGO PLCs. The FTP server does not properly validate the length of a username supplied in the FTP USER command. An oversized username can overwrite stack memory and alter control flow, causing a denial of service or enabling remote execution of attacker-supplied code. The condition is reachable before successful FTP authentication.
Mallory correlates every CVE against your assets, your vendors, and active adversary campaigns. Know which vulnerabilities matter for you, not just which ones are loud.
What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.
What an attacker gets, and what they’ve been doing with it.
If you can’t patch tonight, do this now.
Patch, then assume compromise.
No public exploits tracked yet. Mallory keeps watching.
No public exploit code observed for this vulnerability.
Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.
Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.
18 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.
A pre-authentication buffer overflow in the Nucleus FTP server. An oversized FTP USER-command username can overwrite memory and redirect execution, enabling remote code execution on affected embedded products, including the WAGO 750-831 PLC described.
A pre-authentication buffer-overflow vulnerability in the Nucleus FTP server that enables remote code execution on vulnerable WAGO PLCs. The research demonstrated porting a working RCE exploit from the WAGO 750-852 to the WAGO 750-831 using AI-assisted firmware analysis and testing.
A pre-authentication, stack-based buffer-overflow vulnerability in the Nucleus FTP server USER-command handler that enables remote code execution on affected Nucleus V1-based WAGO PLCs. It was demonstrated as a working RCE exploit capable of executing supplied ARM shellcode and sending attacker-controlled network packets.
A pre-authentication buffer-overflow vulnerability in the Nucleus FTP server deployed on affected WAGO PLCs. It permits an unauthenticated remote attacker to execute arbitrary ARM shellcode; the article describes a working exploit being ported between WAGO 750-852 and 750-831 models.
Query your assets running an affected version, and investigate the blast radius.
Every observed campaign linking this CVE to a named adversary.
Malware families riding this exploit, with evidence and IOCs.
YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.
Cross-references every affected SKU, including bundled OEM variants.
Community discussion across Reddit, Mastodon, and other social sources.