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CVE-2021-4203 is a Linux kernel use-after-free read in the socket option handling path. A race between retrieval of SO_PEERCRED or SO_PEERGROUPS through sock_getsockopt() and concurrent listen() or connect() operations can replace and free peer credential state while it is still being accessed. The flaw affects accesses to sk_peer_pid and sk_peer_cred.
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What an attacker gets, and what they’ve been doing with it.
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Patch, then assume compromise.
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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.
10 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.
Linux kernel race condition involving sk_peer_pid and sk_peer_cred accesses.
Linux kernel race condition in sk_peer_pid and sk_peer_cred access handling.
Linux kernel race condition affecting socket peer PID and credential accesses.
Linux kernel race condition in socket peer PID and credential accesses.
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.