DBI versions before 1.656 for Perl hang on a later open of a DBD::DBM table because a failed open_data does not release the table's lock
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Fix
- Fixed in 1.656
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
- Exploitation: none
- Automatable: yes
- Technical impact: partial
Summary
DBI versions before 1.656 for Perl hang on a later open of a DBD::DBM table because a failed open_data does not release the table's lock. open_data creates the table's lock file and takes an exclusive flock on it for a CREATE, before the checks that can croak: a dbm_mldbm value that is not a module name, a failing tie, or a missing data file. The croak unwinds before the table object is blessed, so nothing releases the lock, and the meta data holding the open descriptor stays cached on the database handle. The dbm_mldbm and dbm_type values come from the DSN or the connect attributes, so a caller that chooses the serializer or the storage backend can trigger the failure. The flock has no timeout, so a later open of that table (even through a separate database handle) blocks for as long as the handle holding the stale lock lives, in the same process or any other.
Timeline
- CVE published
- First seen by cve.now
- CISA SSVC assessment
Exploitation: none · Automatable: yes · Technical impact: partial
- Record last updated
Affected versions
- DBI
fixed in 1.656