CVE-2023-27535: debian debian_linux
Vulnerability summary
CVE-2023-27535 is a medium (CVSS 5.9) vulnerability in debian debian_linux. EPSS estimates a 1.80% chance of exploitation in the next 30 days, higher than 78.1% of scored vulnerabilities. 1 public exploit is recorded.
Advisory lineage
Upstream 0 · Downstream 11 · Related 8Timeline
- 30-03-2023PublishedVulnerability first disclosed.
- 14-10-2026Last modifiedVulnerability information updated.
Description
An authentication bypass vulnerability exists in libcurl <8.0.0 in the FTP connection reuse feature that can result in wrong credentials being used during subsequent transfers. Previously created connections are kept in a connection pool for reuse if they match the current setup. However, certain FTP settings such as CURLOPT_FTP_ACCOUNT, CURLOPT_FTP_ALTERNATIVE_TO_USER, CURLOPT_FTP_SSL_CCC, and CURLOPT_USE_SSL were not included in the configuration match checks, causing them to match too easily. This could lead to libcurl using the wrong credentials when performing a transfer, potentially allowing unauthorized access to sensitive information.
CVSS metrics
6 scores · 6 sources · 1 version- OSV · AlpineEcosystem advisory · calculated5.9MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
- OSV · Red hatEcosystem advisory · calculated5.9MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
- OSV · UbuntuEcosystem advisory · calculated5.9MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
- OSV · DebianEcosystem advisory · calculated5.9MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
- NVDNIST5.9MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS trend
Probability
1.80%
Chance of exploitation in the next 30 days
Percentile
78%
Versus all other CVEs
30-day change
+0.20 pp
From 1.61% on 18-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
1 foundExploit Reference (hackerone.com)
Maturity: unknown
Weaknesses
CWE · root cause- CWE-305Authentication Bypass by Primary WeaknessThe authentication algorithm is sound, but the implemented mechanism can be bypassed as the result of a separate weakness that is primary to the authentication error.
- CWE-287Improper AuthenticationWhen an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.
Affected systems
Redhat10 products
- curl< 0:7.76.1-23.el9_2.1 | < 0:7.61.1-30.el8_8.2
- curl-debuginfo< 0:7.76.1-23.el9_2.1 | < 0:7.61.1-30.el8_8.2
- curl-debugsource< 0:7.76.1-23.el9_2.1 | < 0:7.61.1-30.el8_8.2
- curl-minimal< 0:7.76.1-23.el9_2.1
- curl-minimal-debuginfo< 0:7.76.1-23.el9_2.1 | < 0:7.61.1-30.el8_8.2
Netapp6 products
Debian2 products
- curl< 7.88.1-7
- debian_linuxEOL10.0
Alpine1 product
- curl< 8.0.1-r0 | < 7.88.1-r1 | < 8.0.0-r0
Fedoraproject1 product
- fedoraEOL36
Haxx1 product
- libcurl≥ 7.13.0, ≤ 7.88.1
Splunk1 product
- universal_forwarder≥ 8.2.0, < 8.2.12 | ≥ 9.0.0, < 9.0.6 | 9.1.0
Ubuntu1 product
- curl< 7.35.0-1ubuntu2.20+esm15 | < 7.47.0-1ubuntu2.19+esm8 | < 7.58.0-2ubuntu3.24 | < 7.68.0-1ubuntu2.18 | < 7.81.0-1ubuntu1.10
8 vendors · 23 products
References
24 links- security.netapp.com/advisory/ntap-20230420-0010/Third Party Advisory
