Summary
Out of bounds write in slice-deque
Affected versions of this crate entered a corrupted state if mem::size_of::() % allocation_granularity() != 0 and a specific allocation pattern was used: sufficiently shifting the deque elements over the mirrored page boundary.
This allows an attacker that controls controls both element insertion and removal to corrupt the deque, such that reading elements from it would read bytes corresponding to other elements in the deque. (e.g. a read of T could read some bytes from one value and some bytes from an adjacent one, resulting in a T whose value representation is not meaningful). This is undefined behavior.
The flaw was corrected by using a pair of pointers to track the head and tail of the deque instead of a pair of indices. This pair of pointers are represented using a Rust slice.
Impact
A write operation targets a memory location beyond the intended buffer boundary. Typical impact: memory corruption, crash, or arbitrary code execution.
CVE-2019-15543 has a CVSS score of 9.8 (Critical). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (0.2.0); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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Frequently Asked Questions
- What is CVE-2019-15543? CVE-2019-15543 is a critical-severity out-of-bounds write vulnerability in slice-deque (rust), affecting versions < 0.2.0. It is fixed in 0.2.0. A write operation targets a memory location beyond the intended buffer boundary.
- How severe is CVE-2019-15543? CVE-2019-15543 has a CVSS score of 9.8 (Critical). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of slice-deque are affected by CVE-2019-15543? slice-deque (rust) versions < 0.2.0 is affected.
- Is there a fix for CVE-2019-15543? Yes. CVE-2019-15543 is fixed in 0.2.0. Upgrade to this version or later.
- Is CVE-2019-15543 exploitable, and should I be worried? Whether CVE-2019-15543 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2019-15543 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2019-15543? Upgrade
slice-dequeto 0.2.0 or later.