Security readout for executives and security teams
Plain-English summary
CVE-2023-53159 affects Rust software using the openssl crate before 0.10.55. A specific empty-hostname case can trigger an out-of-bounds read in certificate hostname verification handling. Business impact is limited by high attack complexity and local attack vector scoring, but affected services should still update because TLS verification code is security-sensitive.
Executive priority
Handle in normal vulnerability remediation windows unless the affected code processes untrusted hostname input in sensitive TLS flows. Prioritize systems with external integrations, custom certificate verification, or high availability requirements.
Technical view
The issue is a CWE-126 out-of-bounds read in X509VerifyParamRef::set_host when given an empty string. The bundled CVSS v3.1 score is 4.5, with local attack vector, high complexity, no privileges, no user interaction, changed scope, low confidentiality impact, and low availability impact.
Likely exposure
Exposure is most likely in Rust applications that depend on the sfackler openssl crate earlier than 0.10.55 and call X509VerifyParamRef::set_host with data that may become an empty hostname. The provided data does not identify broader affected products beyond the crate.
Exploitation context
The source bundle does not show CISA KEV listing or other evidence of active exploitation. The condition appears narrow: an empty string passed into the affected API. Do not treat this as internet-wide by default without confirming application use of the vulnerable crate and call path.
Researcher notes
Evidence supports a narrow out-of-bounds read in rust-openssl’s hostname verification parameter API. The provided CPE-style affected entry is sparse, so validate exposure through dependency manifests and code usage rather than product names alone.
Mitigation direction
- Upgrade the Rust openssl crate to version 0.10.55 or later.
- Check vendor and RustSec guidance for any newer remediation notes.
- Reject empty hostnames before certificate verification code paths.
- Rebuild and redeploy applications that vendor or lock the vulnerable crate.
Validation and detection
- Inspect Cargo.lock for openssl crate versions earlier than 0.10.55.
- Search code for X509VerifyParamRef::set_host usage.
- Confirm hostname inputs cannot be empty before reaching certificate verification.
- Run dependency audit tooling against RustSec advisory RUSTSEC-2023-0044.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-126: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2023-53159 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 4.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:C/C:L/I:N/A:L
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:C/C:L/I:N/A:L1.42.7Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
4.5MediumVector: CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:C/C:L/I:N/A:L
Source materials
- CVE List V5 sourceCVE List V5
- https://rustsec.org/advisories/RUSTSEC-2023-0044.htmlCVE reference
- https://github.com/sfackler/rust-openssl/issues/1965CVE reference
- https://crates.io/crates/opensslCVE reference
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Buffer Over-read
Buffer Over-read represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.