Summary
Panic on incorrect date input to simple_asn1
Version 0.6.0 of the simple_asn1 crate panics on certain malformed
inputs to its parsing functions, including from_der and der_decode.
Because this crate is frequently used with inputs from the network, this
should be considered a security vulnerability.
The issue occurs when parsing the old ASN.1 "UTCTime" time format. If an
attacker provides a UTCTime where the first character is ASCII but the
second character is above 0x7f, a string slice operation in thefrom_der_ function will try to slice into the middle of a UTF-8
character, and cause a panic.
This error was introduced in commitd7d39d709577710e9dc8,
which updated simple_asn1 to use time instead of chrono because ofRUSTSEC-2020-159.
Versions of simple_asn1 before 0.6.0 are not affected by this issue.
The patch was applied insimple_asn1 version 0.6.1.
Impact
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 GHSA-3M6F-3GFG-4X56? GHSA-3M6F-3GFG-4X56 is a medium-severity security vulnerability in simple_asn1 (rust), affecting versions = 0.6.0. It is fixed in 0.6.1.
- Which versions of simple_asn1 are affected by GHSA-3M6F-3GFG-4X56? simple_asn1 (rust) versions = 0.6.0 is affected.
- Is there a fix for GHSA-3M6F-3GFG-4X56? Yes. GHSA-3M6F-3GFG-4X56 is fixed in 0.6.1. Upgrade to this version or later.
- Is GHSA-3M6F-3GFG-4X56 exploitable, and should I be worried? Whether GHSA-3M6F-3GFG-4X56 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 GHSA-3M6F-3GFG-4X56 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 GHSA-3M6F-3GFG-4X56? Upgrade
simple_asn1to 0.6.1 or later.