CVE-2016-8616: haxx curl DEPRECATED: Authentication Bypass Issues
Vulnerability summary
CVE-2016-8616 is a medium (CVSS 5.9) DEPRECATED: Authentication Bypass Issues vulnerability in haxx curl. EPSS estimates a 3.47% chance of exploitation in the next 30 days, higher than 89% of scored vulnerabilities.
Not severe (CVSS 3.7, network access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 9 · Related 5Timeline
- 01-08-2018PublishedVulnerability first disclosed.
- 06-08-2024Last modifiedVulnerability information updated.
Description
A flaw was found in curl before version 7.51.0 When re-using a connection, curl was doing case insensitive comparisons of user name and password with the existing connections. This means that if an unused connection with proper credentials exists for a protocol that has connection-scoped credentials, an attacker can cause that connection to be reused if s/he knows the case-insensitive version of the correct password.
CVSS metrics
6 scores · 5 sources · 2 versions- CVE.orgCNA3.7LowCVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:NDiffers
- OSV · AlpineEcosystem advisory · calculated5.9MediumCVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
- OSV · UbuntuEcosystem advisory · calculated3.7LowCVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:NDiffers
- OSV · DebianEcosystem advisory · calculated5.9MediumCVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
EPSS trend
Probability
3.47%
Chance of exploitation in the next 30 days
Percentile
89%
Versus all other CVEs
30-day change
No change 0.00 pp
From 3.47% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.
Alpine1 product
- curl< 7.51.0-r0 | < 7.51.0 | < 7.49.1-r4
Debian1 product
- curl< 7.51.0-1
Haxx1 product
- curl< 7.51.0
The curl project1 product
- curl7.51.0
Ubuntu1 product
- curl< 7.35.0-1ubuntu2.10 | < 7.47.0-1ubuntu2.2
5 vendors · 5 products
References
15 links- bugzilla.redhat.com/show_bug.cgi?id=CVE-2016-8616X Refsource CONFIRMIssue TrackingPatchVendor Advisory
