CVE-2021-29942 — Reorder
HIGHCVE-2021-29942 is a high-severity (CVSS 7.3) Out-of-bounds Write vulnerability in reorder_project reorder. 1 public exploit reference exists, so weaponization risk is real. No vendor fix is recorded yet; mitigation options are listed below.
An issue was discovered in the reorder crate through 2021-02-24 for Rust. swap_index can return uninitialized values if an iterator returns a len() that is too large.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2021-29942 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 385,386 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Description
An issue was discovered in the reorder crate through 2021-02-24 for Rust. swap_index can return uninitialized values if an iterator returns a len() that is too large.
Affected Products
reorderreorder_projectResearch use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Vendor / applianceDetect
Inventory every reorder_project reorder deployment and check each version against the affected-products list above.
Remediation status
No patch has shipped for CVE-2021-29942 yet — track the reorder_project reorder advisory for a fixed release and apply the workarounds below in the meantime.
Mitigate without a patch
Constrain what reaches the vulnerable code: limit the size and shape of untrusted input, isolate the affected component in a sandboxed or least-privileged process, and enable the platform's memory-safety mitigations (ASLR, stack protector, hardened allocator) so an out-of-bounds access is more likely to fail closed than to be exploitable. Alongside that, restrict the management interface to trusted networks and apply the vendor's recommended configuration mitigations.
Frequently Asked Questions
Is CVE-2021-29942 being exploited in your environment?
Detect and block the exploit chain at execution, on systems you cannot patch yet.