An unintended cleartext issue exists in Go before 1.8.4 and 1.9.x before 1.9.1.
An unintended cleartext issue exists in Go before 1.8.4 and 1.9.x before 1.9.1. RFC 4954 requires that, during SMTP, the PLAIN auth scheme must only be used on network connections secured with TLS. The original implementation of smtp.PlainAuth in Go 1.0 enforced this requirement, and it was documented to do so. In 2013, upstream issue #5184, this was changed so that the server may decide whether PLAIN is acceptable. The result is that if you set up a man-in-the-middle SMTP server that doesn't advertise STARTTLS and does advertise that PLAIN auth is OK, the smtp.PlainAuth implementation sends the username and password.
- Published
- Oct 5, 2017
- Updated
- Jun 16, 2026
- EPSS
- 1.1% · 64th percentile
- CWE
- CWE-319
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Report tools
Action score
23
Monitor
Low priority for now.
- CVSS
- 23 / 40 · 5.9 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 1.1%
Affected systems
| Vendor | Product | CPE |
|---|---|---|
| golang | go | cpe:2.3:a:golang:go |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- golang goup to 1.8.3 inclusive
- golang go1.9
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Go | stdlib | from 1.1.0-0 · before 1.8.4 | 1.8.4 |
| Go | stdlib | from 1.9.0-0 · before 1.9.1 | 1.9.1 |
| openSUSE:Tumbleweed | go | before 1.17-1.1 | 1.17-1.1 |
| openSUSE:Tumbleweed | go1.10 | before 1.10.8-8.2 | 1.10.8-8.2 |
| openSUSE:Tumbleweed | go1.11 | before 1.11.13-10.5 | 1.11.13-10.5 |
| openSUSE:Tumbleweed | go1.12 | before 1.12.17-4.8 | 1.12.17-4.8 |
| openSUSE:Tumbleweed | go1.4 | before 1.4.3-12.2 | 1.4.3-12.2 |
| openSUSE:Tumbleweed | go1.9 | before 1.9.7-11.2 | 1.9.7-11.2 |
| Red Hat:devtools:2::el7 | go-toolset-7 | before 0:1.8-10.el7 | 0:1.8-10.el7 |
| Red Hat:devtools:2::el7 | go-toolset-7-build | before 0:1.8-10.el7 | 0:1.8-10.el7 |
| Red Hat:devtools:2::el7 | go-toolset-7-dockerfiles | before 0:1.8-10.el7 | 0:1.8-10.el7 |
| Red Hat:devtools:2::el7 | go-toolset-7-golang | before 0:1.8.5-1.el7 | 0:1.8.5-1.el7 |
| Red Hat:devtools:2::el7 | go-toolset-7-golang-bin | before 0:1.8.5-1.el7 | 0:1.8.5-1.el7 |
| Red Hat:devtools:2::el7 | go-toolset-7-golang-docs | before 0:1.8.5-1.el7 | 0:1.8.5-1.el7 |
| Red Hat:devtools:2::el7 | go-toolset-7-golang-misc | before 0:1.8.5-1.el7 | 0:1.8.5-1.el7 |
| Red Hat:devtools:2::el7 | go-toolset-7-golang-race | before 0:1.8.5-1.el7 | 0:1.8.5-1.el7 |
| Red Hat:devtools:2::el7 | go-toolset-7-golang-src | before 0:1.8.5-1.el7 | 0:1.8.5-1.el7 |
| Red Hat:devtools:2::el7 | go-toolset-7-golang-tests | before 0:1.8.5-1.el7 | 0:1.8.5-1.el7 |
| Red Hat:devtools:2::el7 | go-toolset-7-runtime | before 0:1.8-10.el7 | 0:1.8-10.el7 |
| Red Hat:devtools:2::el7 | go-toolset-7-scldevel | before 0:1.8-10.el7 | 0:1.8-10.el7 |
| Red Hat:enterprise_linux:7::server | golang | before 0:1.9.4-1.el7 | 0:1.9.4-1.el7 |
| Red Hat:enterprise_linux:7::server | golang-bin | before 0:1.9.4-1.el7 | 0:1.9.4-1.el7 |
| Red Hat:enterprise_linux:7::server | golang-docs | before 0:1.9.4-1.el7 | 0:1.9.4-1.el7 |
| Red Hat:enterprise_linux:7::server | golang-misc | before 0:1.9.4-1.el7 | 0:1.9.4-1.el7 |
+2
Same product
golang: all recordsOther highest-scoring records for the same primary product.
- CVE-2018-7187The "go get" implementation in Go 1.9.4, when the -insecure command-line option is used, does not validate the import path (get/vcs.go only 54Plan
- CVE-2018-16873In Go before 1.10.6 and 1.11.x before 1.11.3, the "go get" command is vulnerable to remote code execution when executed with the -u flag and52Plan
- CVE-2021-38297Go before 1.16.9 and 1.17.x before 1.17.2 has a Buffer Overflow via large arguments in a function invocation from a WASM module, when GOARCH42Plan
- CVE-2019-14809net/url in Go before 1.11.13 and 1.12.x before 1.12.8 mishandles malformed hosts in URLs, leading to an authorization bypass in some applica42Plan
- CVE-2015-5739The net/http library in net/textproto/reader.go in Go before 1.4.3 does not properly parse HTTP header keys, which allows remote attackers t42Plan
- CVE-2017-15041Go before 1.8.4 and 1.9.x before 1.9.1 allows "go get" remote command execution.42Plan
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| Go:stdlib | 1.8.4 | Package registry (OSV) |
| Go:stdlib | 1.9.1 | Package registry (OSV) |
| opensuse:go | 1.17-1.1 · openSUSE:Tumbleweed | Package registry (OSV) |
| opensuse:go1.10 | 1.10.8-8.2 · openSUSE:Tumbleweed | Package registry (OSV) |
| opensuse:go1.11 | 1.11.13-10.5 · openSUSE:Tumbleweed | Package registry (OSV) |
| opensuse:go1.12 | 1.12.17-4.8 · openSUSE:Tumbleweed | Package registry (OSV) |
| opensuse:go1.4 | 1.4.3-12.2 · openSUSE:Tumbleweed | Package registry (OSV) |
| opensuse:go1.9 | 1.9.7-11.2 · openSUSE:Tumbleweed | Package registry (OSV) |
| red hat:go-toolset-7 | 0:1.8-10.el7 · Red Hat:devtools:2::el7 | Package registry (OSV) |
| red hat:go-toolset-7-build | 0:1.8-10.el7 · Red Hat:devtools:2::el7 | Package registry (OSV) |
| red hat:go-toolset-7-dockerfiles | 0:1.8-10.el7 · Red Hat:devtools:2::el7 | Package registry (OSV) |
| red hat:go-toolset-7-golang | 0:1.8.5-1.el7 · Red Hat:devtools:2::el7 | Package registry (OSV) |
| red hat:go-toolset-7-golang-bin | 0:1.8.5-1.el7 · Red Hat:devtools:2::el7 | Package registry (OSV) |
| red hat:go-toolset-7-golang-docs | 0:1.8.5-1.el7 · Red Hat:devtools:2::el7 | Package registry (OSV) |
| red hat:go-toolset-7-golang-misc | 0:1.8.5-1.el7 · Red Hat:devtools:2::el7 | Package registry (OSV) |
| red hat:go-toolset-7-golang-race | 0:1.8.5-1.el7 · Red Hat:devtools:2::el7 | Package registry (OSV) |
| red hat:go-toolset-7-golang-src | 0:1.8.5-1.el7 · Red Hat:devtools:2::el7 | Package registry (OSV) |
| red hat:go-toolset-7-golang-tests | 0:1.8.5-1.el7 · Red Hat:devtools:2::el7 | Package registry (OSV) |
| red hat:go-toolset-7-runtime | 0:1.8-10.el7 · Red Hat:devtools:2::el7 | Package registry (OSV) |
| red hat:go-toolset-7-scldevel | 0:1.8-10.el7 · Red Hat:devtools:2::el7 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- No user action is required.
- Special conditions such as timing or configuration are required.
If successful
- Confidentiality
- high · data can be read
- Integrity
- none
- Availability
- none
- Attack vector
- Network
- Attack complexity
- High
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- None
- Availability impact
- None
Weakness class (CWE)
CWE-319 · Cleartext Transmission of Sensitive InformationCVSS vector
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
nvd-primary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
ATT&CK techniques
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for all 385,000+ vulnerabilities; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpChange log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
- www.securityfocus.com/bid/101197
- access.redhat.com/errata/RHSA-2017:3463
- access.redhat.com/errata/RHSA-2018:0878
- github.com/golang/go/issues/22134
- golang.org/cl/68023
- golang.org/cl/68210
- groups.google.com/d/msg/golang-dev/RinSE3EiJBI/kYL7zb07AgAJ
- security.gentoo.org/glsa/201710-23
Vendor advisories and official records. Exploit/PoC links are deliberately left out.