CVE-2021-28034: 
Rust vulnerability analysis and mitigation

An issue was discovered in the stack_dst crate before version 0.6.1 for Rust. The vulnerability (CVE-2021-28034) involves a double free condition that can occur upon a val.clone() panic due to the push_inner behavior. The issue was disclosed on March 5, 2021 (NVD, RustSec).

The vulnerability stems from the push_inner function implementation in the stack_dst crate. When the function increases the internal length of the array and then calls val.clone(), a panic during the clone operation can trigger a double free condition. This occurs because the array length is increased before the clone operation is completed successfully. The issue received a CVSS v3.1 base score of 9.8 (CRITICAL) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H (NVD, RustSec).

If exploited, this vulnerability can lead to memory corruption through a double free condition. This could potentially result in program crashes or undefined behavior when using the affected stack_dst crate versions (RustSec).

The vulnerability can be triggered when using the push_cloned function in the StackA implementation, specifically when a panic occurs during the val.clone() operation. The attack vector is network-accessible and requires no special privileges or user interaction to exploit (RustSec).

The vulnerability was fixed in version 0.6.1 of the stack_dst crate. The fix involves modifying the implementation to increase the array length after elements are cloned, rather than before. Users should upgrade to version 0.6.1 or later to address this vulnerability (RustSec).