GHSA-75xq-5h9v-w6px is a medium-severity (CVSS 5.3) CWE-77 vulnerability in net-imap. O3 Security confirms whether GHSA-75xq-5h9v-w6px is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
net-imap vulnerable to command Injection via unvalidated Symbol inputs
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for GHSA-75xq-5h9v-w6px.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
GHSA-75xq-5h9v-w6px plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 356,530 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
net-imap💎net-imap💎net-imapReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects RubyGems packages — download data is not available via public APIs for these ecosystems.
Description
Summary
Symbol arguments to commands are vulnerable to a CRLF Injection / IMAP Command injection via Symbol arguments passed to IMAP commands.
Details
Symbol arguments represent IMAP "system flags", which are formatted as "atoms" (with no quoting) with a "\" prefix. Vulnerable versions of Net::IMAP sends the symbol name directly to the socket, with no validation.
Because the Symbol input is unvalidated, it could contain invalid flag characters, including SP and CRLF, which could be used to finish the current command and inject new commands.
Although IMAP flag arguments are only valid input for a few IMAP commands, most Net::IMAP commands use generic argument handling, and will allow Symbol (flag) inputs.
Note also that the list of valid symbol inputs should be restricted to an enumerated set of standard RFC defined flag types, which have each been given specific defined semantics. Any user-provided values outside of that list of standard "system flags" needs to use the IMAP keyword syntax, which are sent as atoms, i.e: string inputs. Under no circumstances should #to_sym ever be called on unvetted user-provided input: that will always be a bug in the calling code for the simple reason that user_input_atom is as \user_input_atom.
For forward compatibility with future IMAP extentions, Net::IMAP, does not restrict flag inputs to an enumerated list. That is the responsibility of the calling application code, which knows which flag semantics are valid for its context.
Impact
If a developer passes user-controlled input as a Symbol to most Net::IMAP commands, an attacker can append CRLF sequence followed by a new IMAP command (like DELETE mailbox).
Mitigation
-
Upgrade to a version of Net::IMAP that validates Symbols are valid as an IMAP
flag. -
User-provided input should never be able to control calling
#to_symon string arguments.For example, do not unsafely serialize and deserialize command arguments (e.g. with YAML or Marshal) in a way that could create unvetted Symbol arguments.
-
For the few IMAP commands which do allow
flagarguments, it may be appropriate to hard-code Symbol arguments or restrict them to an enumerated list which is valid for the calling application.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 💎RubyGems | net-imap | ≥ 0.6.0&&< 0.6.4 | 0.6.4 |
| 💎RubyGems | net-imap | ≥ 0.5.0&&< 0.5.14 | 0.5.14 |
| 💎RubyGems | net-imap | all versions | 0.4.24 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for net-imap. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update net-imap to 0.6.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-75xq-5h9v-w6px is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-75xq-5h9v-w6px is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-75xq-5h9v-w6px. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
This command injection flaw is limited to the injection of IMAP commands. Arbitrary code execution is not a risk of this flaw and so the impact is limited to email systems.
Frequently Asked Questions
Is GHSA-75xq-5h9v-w6px in your dependencies?
O3 detects GHSA-75xq-5h9v-w6px across RubyGems dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.