If effectively is legal there, albeit not officially. In brief, a law in 2007 was put in place - better late than never!! - but never actually implemented:

the Venezuelan government enacted the Organic Law on the Right of Women to a Violence-Free Life. Article 56 of the new law prohibits the trafficking of women, girls, and adolescents for purposes of sexual exploitation, prostitution, forced labor, or slavery, and prescribes punishments of 15 to 20 years' imprisonment.

However, despite the policy efforts to combat human trafficking, many of the promises laid out in the Organic Law on the Right of Women to a Violence-Free Life were ignored

As a result, despite the public efforts of Venezuela to pass the Organic Law on the Right of Women to a Violence-Free Life, many of the policy elements were never fully implemented, if at all.

the policy provisions do not address the trafficking of adult males or boys... As a result, the issue has been framed in the country as a gender-specific one, when, at least 18% of men are victims of human trafficking

Trafficking in Persons report, the United States said it had lowered Venezuela's ranking to Tier 3, the lowest grade possible