Perl: Improper Certificate Validation
CVE-2023-31486 is a high-severity improper certificate validation vulnerability in Perl, with a CVSS 3.1 base score of 8.1 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists version 5.38.0 as the first without the flaw, so updating Perl to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 1.74% chance of exploitation within 30 days, higher than 78% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Perl to 5.38.0 or a later version.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
Version data comes from NVD's product matching. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- HighSuccess depends on conditions outside the attacker's control.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 8.1 | High | NVD |
| CVSS 3.1 | 8.1 | High | CISA (ADP) |
Official description
HTTP::Tiny before 0.083, a Perl core module since 5.13.9 and available standalone on CPAN, has an insecure default TLS configuration where users must opt in to verify certificates.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Certificate Validation
The product does not validate, or incorrectly validates, a certificate.
How developers prevent this class of flaw
- Certificates should be carefully managed and checked to assure that data are encrypted with the intended owner's public key.
- If certificate pinning is being used, ensure that all relevant properties of the certificate are fully validated before the certificate is pinned, including the hostname.
More Improper Certificate Validation vulnerabilities (CWE-295)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
- openwall.com/lists/oss-security/2023/04/29/1Mailing List
- openwall.com/lists/oss-security/2023/05/03/3Mailing List
- blog.hackeriet.no/perl-http-tiny-insecure-tls-default-affects-cpan-modules/Mitigation, Third Party Advisory
- github.com/chansen/p5-http-tiny/pull/153
- openwall.com/lists/oss-security/2023/04/18/14Mailing List
Third-party and government advisories
- openwall.com/lists/oss-security/2023/05/07/2Mailing List, Third Party Advisory
- openwall.com/lists/oss-security/2023/05/03/4Mailing List, Third Party Advisory
Other references
Other vulnerabilities in Perl
- 8.4 High severity
- 9.1 Critical severity
- 9.8 Critical severity
- 8.4 High severity
- 7.8 High severity
- 7.8 High severity
Recent Improper Certificate Validation vulnerabilities
- 9.8 Critical severity
- 8.1 High severity
- 8.8 High severity
- 9.8 Critical severity
- 7.8 High severity
Android Framework Privilege Escalation Exploited
- 7.5 High severity
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