Loading vulnerability…
CVE-2021-3634 is an out-of-bounds memory-access flaw in libssh versions before 0.9.6 during SSH key re-exchange. libssh historically tracked the session_id and secret_hash buffers using a shared length value. Although both buffers initially have equal lengths, a key re-exchange can negotiate a key-exchange algorithm with a differently sized hash output. This leaves secret_hash with a length that does not match the preserved session_id. Subsequent zeroing or reuse of session_id during another re-exchange can use the incorrect length and access memory outside the session_id buffer.
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.
12 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.
A Linux kernel vulnerability referenced by the advisory; no technical details are provided in this content.
CVE listed as addressed by this advisory; no technical description is provided in the content.
A vulnerability addressed by the OpenShift API for Data Protection 1.0.4 security update; no technical details are provided.
Unknown.
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.